List of steps to reproduce (step by step, including full links if applicable):
- Install a vanilla MediaWiki 1.37.1 on a Linux server, with VisualEditor
- Click "Edit" to edit any page using VisualEditor
- VisualEditor displays the dialog: "Revision IDs returned by the server do not match (document: undefined, metadata: nnn)", where nnn is an integer such as 123.
What happens?:
No pages on the wiki are editable using VisualEditor.
What should have happened instead?:
VisualEditor should edit the page.
Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc.:
MW 1.37.1, installed using the standard MediaWiki installer.
PHP 7.4.28
Google Chrome on Linux 100.0.4896.75 (Official Build) (x86_64)
Debugging information:
The error is thrown by function ve.init.mw.ArticleTarget.prototype.parseMetadata in extensions/VisualEditor/modules/ve-mw/init/targets/ve.init.mw.ArticleTarget.js. The problem is that this.doc.documentElement.getAttribute( 'about' ) is null, so docRevId remains undefined. What would cause this behavior?
The error message ID is 'visualeditor-loaderror-revidconflict'.
Here is the relevant code:
// `undefined` indicates that the page doesn't exist
docRevId = undefined;
aboutDoc = this.doc.documentElement && this.doc.documentElement.getAttribute( 'about' );
if ( aboutDoc ) {
docRevIdMatches = aboutDoc.match( /revision\/([0-9]*)$/ );
if ( docRevIdMatches.length >= 2 ) {
docRevId = parseInt( docRevIdMatches[ 1 ] );
}
}
// There is no docRevId in source mode (doc is just a string), new visual documents, or when
// switching from source mode with changes.
if ( this.getDefaultMode() === 'visual' && !( this.switched && this.fromEditedState ) && docRevId !== this.revid ) {
if ( this.retriedRevIdConflict ) {
// Retried already, just error the second time.
this.loadFail( 've-api', { errors: [ {
code: 've-api',
html: mw.message( 'visualeditor-loaderror-revidconflict',
String( docRevId ), String( this.revid ) ).parse()
} ] } );
}
