F12 developer tools console error messages
This content refers to an older version of F12 developer tools. Please visit our latest F12 tools documentation.
The F12 tools console can report error and informational messages that occur during runtime. This article describes the error messages and offers suggestions for how to fix the errors.
Introduction
F12 tools console error messages provide codes that provide information about the error, for example, SEC7111 or HTML1114. These codes and messages appear in both the Console and Script tabs in F12 tools. For JavaScript programmers, these codes are thrown from Windows Internet Explorer. ActiveX and Browser extension developers can also send these errors and messages.
The tables later in this topic are broken into sections that include the code, the message, a description, and when appropriate, suggestions to fix the problem. While the descriptions in the table provide a starting point for debugging problems, the best way to get information is to visit online developer forums or the Internet Explorer developer center.
Security errors
These errors are in the form SEC7xxx, such as SEC7113. These reflect security conditions that Windows Internet Explorer 9 enforces, such as mixed content, and Tracking Protection.
| Code | Message | Description | Suggested fix |
|---|---|---|---|
SEC7111 |
"HTTPS security is compromised by [name of resource]" |
Secure Hypertext Transfer Protocol (HTTPS) page also has unsecured (mixed) content. |
Do not include unsecured content on a HTTPS page. |
SEC7112 |
"Script from [URL] was blocked due to mime type mismatch" |
The HTTP response header for the JavaScript file that is specified by the URL has an "X-Content-Type-Options: nosniff "header, and did not have a content type declaration. |
Add the correct content type for the JavaScript file (such as text/javascript, application/javascript, and so on) See MIME-Handling Changes in Internet Explorer for more information and a full list of content types. |
SEC7113 |
"CSS was ignored due to mime type mismatch" |
An imported style sheet was not used due to the wrong MIME type in the HTTP header. |
Ensure style sheet file is delivered with the proper HTTP response header, which includes a content type of text\css. See MIME-Handling Changes in Internet Explorer for more information. |
SEC7114 |
"A download in this page was blocked by Tracking Protection.[URL provided here]" |
User blocked script or content by using Tracking Protection. |
None - user initiated. |
SEC7115 |
":visited and :link styles can only differ by color. Some styles were not applied to :visited." |
More than one attribute, such as font or size, were changed by using the visited and link styles. |
Change only the color attribute. |
Note For websites in a users trusted security zone, Internet Explorer will not check the MIME type of a style sheet.
HTML codes
These codes are in the form of HTML1xxx, such as HTML1115. They can specify errors or states that the developer might or might not be able to control.
| Code | Message | Description | Suggested fix |
|---|---|---|---|
HTML1112 |
"Codepage restart from [encoding] to [encoding]" |
A codepage was specified that was different than the server. |
Use same codepage as server to avoid message. |
HTML1113 |
Document mode restart from [mode] to [mode] |
The webpage requires a different document mode than the browser was currently set to. |
This message can occur when the user browses from another page, so it can be out of the developer's control. |
HTML1114 |
"Codepage [codepage] from [domain] overrides conflicting codepage [codepage] from [domain]" |
Conflicting codepages specified in the http header and markup for a website. |
Fix codepage conflict. |
HTML1115 |
"X-UA-Compatible META tag ("[META tag]") ignored because document mode is already finalized" |
Typically the "META" tag was placed after a "Script" or "Style" declaration, which fixed the document mode for the page. |
Move the X-UA-Compatible META tag as early in the header as possible. A good practice is to put it immediately after the "<title>" and charset value. |
HTML1116 |
"X-UA-Compatible META tag ("[META tag]") ignored because of earlier X-UA-Compatible META tag ("[META tag]")" |
There are more than one "X-UA-Compatible""META" tag in the "<head>" section of the source code. |
Remove all but one "X-UA-Compatible META" tag, and ensure it is as early in the header as possible. A good practice is to put it immediately after the "<title>" and charset value. |
HTML1200 |
"[domain] is on the Internet Explorer 9 Compatibility View List ('[path to local Compatibility View List]')." |
The current website is listed on Internet Explorer's internal list. |
Website developers can follow guidelines to remove their site from the Compatibility View list. The list is periodically updated by Microsoft, so changes can be downloaded and reflected. |
HTML1201 |
"[domain] is a website you've added to Compatibility View." |
The user has clicked the Compatibility View button for the current website or added it through the Compatibility View settings. |
User initiated. |
HTML1202 |
"[domain] is running in Compatibility View because "Display intranet sites in Compatibility View" is checked." |
The user has selected the Display intranet sites in Compatibility View check box in the Compatibility View settings. |
User needs to press Alt + T, click Compatibility View settings, and then clear the Display intranet sites in Compatibility View check box. |
HTML1203 |
"[domain] has been configured to run in Compatibility View through Group Policy." |
The network administrator has specified that the webpage be run in Compatibility View. |
User needs to contact the network administrator. |
HTML1204 |
"[domain] is running in Compatibility View because "Display all websites in Compatibility View" is checked." |
The user has selected the Display all websites in Compatibility View check box in the Compatibility View settings. |
User needs to press Alt + T, click Compatibility View settings, and then clear theDisplay all websites in Compatibility View check box. |
HTML1300 |
"Navigation occurred" |
A new page was navigated to, or the current page was refreshed. |
This is an informational message and not an error. To filter this message, right click the console pane, click Filter, and then uncheck Info. |
HTML5 parser warnings
The following warnings can occur as part of the validation that is performed during HTML parsing. These warnings don't necessarily mean a page is broken, but that the provided HTML is invalid per the HTML5 standard. Content created according to earlier versions of the HTML or XHTML specifications might not be valid in HTML5, in particular with respect to the use of DOCTYPEs. For more information, see Creating Standards-Enabled Websites.
Common causes of these warnings include missing or additional characters, and mismatched tags. When these warnings are resolved, it can improve compatibility with older browsers and improve a webpage’s compliance with the HTML5 standard. To help identify the source of a warning, Internet Explorer includes line and character offset information along with a link pointing to the location where the problem was found.
| Code | Message |
|---|---|
HTML1400 |
"Unexpected character at start of numeric character reference. Expected [0-9]." |
HTML1401 |
"Unexpected character at start of hexadecimal numeric character reference. Expected [0-9], [a-f], or [A-F]." |
HTML1402 |
"Character reference is missing an ending semicolon ";"." |
HTML1403 |
"Numeric character reference does not resolve to a valid character." |
HTML1404 |
"Unrecognized named character reference." |
HTML1405 |
"Invalid character: U+0000 NULL. Null characters should not be used." |
HTML1406 |
"Invalid tag start: "<?". Question marks should not start tags." |
HTML1407 |
"Invalid tag name. First character should match [a-zA-Z]." |
HTML1408 |
"Invalid end tag "</>". End tags should not be empty." |
HTML1409 |
"Invalid attribute name character. Attribute names should not contain ("),('),(<), or (=)." |
HTML1410 |
"Invalid unquoted attribute value. Unquoted attribute values should not contain ("), ('), (<), (=), or (`)." |
HTML1411 |
"Unexpected end of file." |
HTML1412 |
"Malformed comment. Comments should start with "<!-- "." |
HTML1413 |
"Unexpected character: U+003E GREATER-THAN SIGN (>)" |
HTML1414 |
"Unexpected character: U+0021 EXCLAMATION MARK (!)" |
HTML1415 |
"Unexpected character: U+002D HYPHEN-MINUS (-)" |
HTML1416 |
"Unexpected character in comment end. Expected "-->"." |
HTML1417 |
"Empty DOCTYPE. The shortest valid doctype is "<!DOCTYPE html>"." |
HTML1418 |
"Unexpected character in DOCTYPE." |
HTML1419 |
"Unexpected keyword in DOCTYPE. Expected "PUBLIC" or "SYSTEM"." |
HTML1420 |
"Unexpected quote after "PUBLIC" or "SYSTEM" keyword. Expected whitespace." |
HTML1421 |
"Malformed end tag. End tags should not contain attributes." |
HTML1422 |
"Malformed start tag. A self closing slash should be followed by a U+003E GREATER-THAN SIGN (>)." |
HTML1423 |
"Malformed start tag. Attributes should be separated by whitespace." |
HTML1424 |
"Invalid character " |
HTML1500 |
"Tag cannot be self-closing. Use an explicit closing tag." |
HTML1501 |
"Unexpected end of file." |
HTML1502 |
"Unexpected DOCTYPE. Only one DOCTYPE is allowed and it must occur before any elements." |
HTML1503 |
"Unexpected start tag." |
HTML1504 |
"Unexpected end tag." |
HTML1505 |
"Unexpected character token." |
HTML1506 |
"Unexpected token." |
HTML1507 |
"Unexpected character: U+0000 NULL. Null characters should not be used." |
HTML1508 |
"Unmatched end tag." |
HTML1509 |
"Unmatched end tag." |
HTML1510 |
"Required nodes not in scope." |
HTML1511 |
"Unexpected head-level element encountered outside of "<head>"." |
HTML1512 |
"Unmatched end tag." |
HTML1513 |
"Extra "<html>" tag found. Only one "<html>" tag should exist per document." |
HTML1514 |
"Extra "<body>" tag found. Only one "<body>" tag should exist per document." |
HTML1515 |
"Found "<frameset>" too far down in the document. This tag should occur before a "<body>" is created." |
HTML1516 |
"Invalid nesting. A header tag such as "<h1>" or "<h2>" should not be placed within another header tag." |
HTML1517 |
"Invalid nesting. A "<form>" tag should not be placed within another "<form>"." |
HTML1518 |
"Invalid nesting. A "<button>" tag should not be placed within another "<button>"." |
HTML1519 |
"Invalid nesting. An "<a>" tag should not be placed within another "<a>"." |
HTML1520 |
"Unexpected start tag: The "<isindex>" element is deprecated and should not be used." |
HTML1521 |
"Unexpected "</body>" or end of file. All open elements should be closed before the end of the document." |
HTML1522 |
"Invalid end tag: "</br>". Use "<br>" or "<br/>" instead." |
HTML1523 |
"Overlapping end tag. Tags should be structured like "<b><i></i></b>" instead of "<b><i></b></i>"." |
HTML1524 |
"Invalid DOCTYPE. The shortest valid doctype is "<!DOCTYPE html>"." |
HTML1525 |
"Unexpected HTML tag found inside foreign content (MathML/SVG)." |
HTML1526 |
"Invalid nesting. A "<nobr>" tag should not be placed within another "<nobr>"." |
HTML1527 |
"DOCTYPE expected. The shortest valid doctype is "<!DOCTYPE html>"." |
HTML1528 |
"Unexpected "<image>" in HTML content. Use "<img>" instead." |
HTML1529 |
"Invalid xmlns:xlink attribute value. The value must be "http://www.w3.org/1999/xlink"." |
HTML1530 |
"Text found within a structural table element. Table text may only be placed inside "<caption>", "<td>", or "<th>" elements." |
HTML1531 |
"Invalid xmlns attribute value. For SVG elements the value must be "http://www.w3.org/2000/svg"." |
HTML1532 |
"Invalid xmlns attribute value. For MathML elements the value must be "http://www.w3.org/1998/Math/MathML"." |
CSS codes
These errors are in the form CSS31xx and are related to "Web Open Font Format (WOFF)", and "Embedded OpenType font (EOT)" source and host server problems.
| Code | Message | Description | Suggested fix |
|---|---|---|---|
CSS3111 |
"@font-face encountered unknown error" |
An unknown problem was encountered with the "Web Open Font Format (WOFF)", and "Embedded OpenType font (EOT)" of the Cascading Style Sheets (CSS) font. |
Check source of "WOFF" fonts. Try alternate font face or source to see if problem reproduces. |
CSS3112 |
"@font-face failed WOFF integrity check" |
The "Web Open Font Format (WOFF)" font is possibly corrupt, incomplete, or not the correct format. |
Check source of the fonts. Try known good font face or source to see if problem reproduces. |
CSS3113 |
"@font-face mismatch between document origin and EOT root string" |
The font cannot be used because the URL(rootstring) in the "Embedded OpenType font (EOT)" does not match the domain of the document using the font. |
The URL checksum in the "EOT" rootstring might be incorrect, indicating a corrupt or altered URL for the font. Ensure that the font is licensed or has permissions for the website where the fonts are being used. |
CSS3114 |
"@font-face failed OpenType embedding permission check. Permission must be Installable." |
The font-face does not have permissions to install with the current webpage. |
Obtain the correct permission or licenses for embedding the font. |
CSS3115 |
"@font-face unable to load invalid OpenType font." |
The font-face is not valid for this use. |
Obtain the permission or licenses for the current and valid font-face. |
CSS3116 |
"@font-face failed cross-origin request. No Access-Control-Allow-Origin header." |
The font might not be configured for cross-domain access. |
The font is not served from the same origin as the document. Ensure that the host serving the font allows the use of this font by using the "Access-Control-Allow-Origin"HTTP header. |
CSS3117 |
"@font-face failed cross-origin request. Resource access is restricted." |
The "Access-Control-Allow-Origin" header might not be configured correctly or the font host might not allow this font to be used by your page. |
Ensure that correct permissions and a correctly configured HTTP response header that has cross-domain access origin for the host serving the fonts. |
Scalable Vector Graphics (SVG) codes
F12 tools do not currently support extensive Scalable Vector Graphics (SVG) debugging, but several console messages are displayed to help debug SVG code.
| Code | Message | Description | Suggested fix |
|---|---|---|---|
SVG5601 |
"SVG Path data has incorrect format and could not be completely parsed." |
The SVG Path string is not formatted correctly, or contains unrecognized commands. |
Check format of commands. |
SVG5602 |
"SVG Point list has incorrect format and could not be completely parsed." |
The list of points used for an element, such as a polyline, is not correctly formatted. |
Ensure that points are complete and correctly formatted for the users coordinate system. |
Script codes
JavaScript runtime errors are also reported in F12 tools. These errors are in the form SCRIPT50xx, such as SCRIPT5001. These errors are documented on the JavaScript Errors page.
XML codes
The F12 tools console can report XML codes. These errors are in the form of XML5xxx, such as XML5603. For more information about XML, see the XmlLite Reference.
| Code | Message |
|---|---|
XML5001 |
"Applying Integrated XSLT Handling." |
XML5601 |
"MX_E_MX" |
XML5602 |
"Unexpected end of input." |
XML5603 |
"Unrecognized encoding." |
XML5604 |
"Unable to switch the encoding." |
XML5605 |
"Unrecognized input encoding signature." |
XML5606 |
"WC_E_WC" |
XML5607 |
"Whitespace expected." |
XML5608 |
"Semicolon expected." |
XML5609 |
"Expected ">"." |
XML5610 |
"Quote character expected." |
XML5611 |
"Expected "="." |
XML5612 |
"The < character is not allowed in attributes values." |
XML5613 |
"Hexadecimal digit expected." |
XML5614 |
"Decimal digit expected." |
XML5615 |
"Expected "["." |
XML5616 |
"Expected "("." |
XML5617 |
"Illegal XML character." |
XML5618 |
"Illegal name character." |
XML5619 |
"Incorrect document syntax." |
XML5620 |
"Incorrect CDATA section syntax." |
XML5621 |
"Incorrect comment syntax." |
XML5622 |
"Incorrect conditional section syntax." |
XML5623 |
"Incorrect ATTLIST declaration syntax." |
XML5624 |
"Incorrect DOCTYPE declaration syntax." |
XML5625 |
"Incorrect ELEMENT declaration syntax." |
XML5626 |
"Incorrect ENTITY declaration syntax." |
XML5627 |
"Incorrect NOTATION declaration syntax." |
XML5628 |
"Expected "NDATA"." |
XML5629 |
"Expected "PUBLIC"." |
XML5630 |
"Expected "SYSTEM"." |
XML5631 |
"Invalid name." |
XML5632 |
"Only one root element is allowed." |
XML5633 |
"End-tag name does not match the corresponding start-tag name." |
XML5634 |
"An attribute with the same name already exists on this element." |
XML5635 |
"An XML declaration is only allowed at the beginning of the file." |
XML5636 |
"Leading "xml"." |
XML5637 |
"Incorrect text declaration syntax." |
XML5638 |
"Incorrect XML declaration syntax." |
XML5639 |
"Incorrect encoding name syntax." |
XML5640 |
"Incorrect public identifier syntax." |
XML5641 |
"Parameter entity references are not allowed within markup declarations in an internal DTD subset." |
XML5642 |
"The replacement text for parameter entity references used between markup declarations must itself contain a series of complete markup declarations." |
XML5643 |
"A parsed entity must not contain a direct or indirect reference to itself." |
XML5644 |
"The content of the specified entity is not well-formed." |
XML5645 |
"The specified entity has not been declared." |
XML5646 |
"Entity reference cannot contain the name of an unparsed entity." |
XML5647 |
"Attribute values must not contain direct or indirect references to external entities." |
XML5648 |
"Incorrect processing instruction syntax." |
XML5649 |
"Incorrect system identifier syntax." |
XML5650 |
"Expected a question mark (?)." |
XML5651 |
"The CDATA-section-close delimiter "]]>" must not be used in element content." |
XML5652 |
"Not all chunks of data have been read." |
XML5653 |
"DTD was found but is prohibited." |
XML5654 |
"Found xml:space attribute with invalid value. Valid values are "preserve" or "default"." |
XML5655 |
"NC_E_NC" |
XML5656 |
"Illegal qualified name character." |
XML5657 |
"Multiple colons ":" must not occur in a qualified name." |
XML5658 |
"A colon ":" must not occur in a name." |
XML5659 |
"Declared prefix." |
XML5660 |
"The specified prefix has not been declared." |
XML5661 |
"Non-default namespace declarations must not have an empty URI." |
XML5662 |
"The "xml" prefix is reserved and must have the URI "http://www.w3.org/XML/1998/namespace"." |
XML5663 |
"The "xmlns" prefix is reserved for use by XML." |
XML5664 |
"The xml namespace URI (http://www.w3.org/XML/1998/namespace) must only be assigned to the prefix "xml"." |
XML5665 |
"The xmlns namespace URI (http://www.w3.org/2000/xmlns/) is reserved and must not be used." |
XML5666 |
"SC_E_SC" |
XML5667 |
"Exceeded maximum depth of nested elements." |
XML5668 |
"Exceeded maximum number of entity expansions." |
XML5669 |
"WR_E_WR" |
XML5670 |
"WR_E_NONWHITESPACE: writer: specified string is not whitespace." |
XML5671 |
"WR_E_NSPREFIXDECLARED: writer: namespace prefix is already declared with a different namespace." |
XML5672 |
"WR_E_NSPREFIXWITHEMPTYNSURI: writer: cannot use prefix with empty namespace URI." |
XML5673 |
"WR_E_DUPLICATEATTRIBUTE: writer: duplicate attribute." |
XML5674 |
"WR_E_XMLNSPREFIXDECLARATION: writer: can not redefine the xmlns prefix." |
XML5675 |
"WR_E_XMLPREFIXDECLARATION: writer: xml prefix must have the http://www.w3.org/XML/1998/namespace URI." |
XML5676 |
"WR_E_XMLURIDECLARATION: writer: xml namespace URI (http://www.w3.org/XML/1998/namespace) must be assigned only to prefix "xml"." |
XML5677 |
"WR_E_XMLNSURIDECLARATION: writer: xmlns namespace URI (http://www.w3.org/2000/xmlns/) is reserved and must not be used." |
XML5678 |
"WR_E_NAMESPACEUNDECLARED: writer: namespace is not declared." |
XML5679 |
"WR_E_INVALIDXMLSPACE: writer: invalid value of xml:space attribute (allowed values are "default" and "preserve")." |
XML5680 |
"WR_E_INVALIDACTION: writer: performing the requested action would result in invalid XML document." |
XML5681 |
"WR_E_INVALIDSURROGATEPAIR: writer: input contains invalid or incomplete surrogate pair." |
XML5682 |
"Unexpected character in character entity. Expected a decimal digit." |
XML5683 |
"Unexpected character in character entity. Expected a hexadecimal digit." |
XML5684 |
"The Unicode value of the specified character entity is invalid." |
XML5685 |
"Invalid encoding." |
XML5686 |
"Unspecified XML error." |