@Herzi.Pinki: Hi, the MediaWiki-extensions-Gadgets project is for the PHP extension which allows to load gadgets, not for random gadgets themselves, so this might be the wrong place and you may have to report this on-wiki if this turns out to be broken code in the gadget itself...

Which exact wiki is this about? Please include URLs to reproduce a bug when reporting a bug. See https://www.mediawiki.org/wiki/How_to_report_a_bug :) Thanks!

the problem occurs on Commons: https://commons.wikimedia.org/wiki/Help:Gadget-ImageAnnotator
The issue is also reported here: https://commons.wikimedia.org/wiki/MediaWiki_talk:Gadget-ImageAnnotator.js#Problem

On-wiki content like user scripts, gadgets, templates, custom CSS are local features and managed independently on each wiki. Usually Phabricator is used for MediaWiki, MediaWiki extensions, or server configuration and I'd say that https://commons.wikimedia.org/wiki/MediaWiki_talk:Gadget-ImageAnnotator.js is the place to discuss the issue, but as Commons exists I'm going to leave it to the Commons folks to decide this...

The gadget has currently no maintainer and is very old. :( Maybe something is deprecated or some kind of caching issue.

LAPI is not maintained as well, and should probably be replaced by the MWJS stuff.

var revision_id = LAPI.WP.revisionFromHtml( request.responseText );
if ( !revision_id ) {
	if ( doc.isFake && ( typeof doc.dispose === 'function' ) ) { doc.dispose(); }
	failureFunc( request, new Error( '#Version inconsistency after saving. Please reload the page.' ) );
	return;
}

I applied the fix by Lupo himself. So this is probably fixed!?