Exactly what did you do to provoke this error?

I only open index.php: http://wiki.smallbusiness-webdesign.de/index.php

Only "Hauptseite" seems to not work. Other pages like http://wiki.smallbusiness-webdesign.de/index.php/Spezial:Version or http://wiki.smallbusiness-webdesign.de/index.php/Spezial:Zufällige_Seite works.

Can you but wfDebugDieBacktrace() before that line?

MediaWiki internal error.

Original exception: exception 'MWException' in C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\GlobalFunctions.php:983
Stack trace:
#0 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\parser\ParserCache.php(175): wfDebugDieBacktrace()
#1 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedRevs.class.php(809): ParserCache->save(Object(ParserOutput), Object(FlaggedArticle), Object(User))
#2 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedArticleView.php(532): FlaggedRevs::stableVersionIsSynced(Object(FlaggedRevision), Object(FlaggedArticle), Object(ParserOutput), NULL)
#3 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedArticleView.php(263): FlaggedArticleView->showStableVersion(Object(FlaggedRevision), '', NULL)
#4 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedRevs.hooks.php(1651): FlaggedArticleView->setPageContent(false, true)
#5 [internal function]: FlaggedRevsHooks::onArticleViewHeader(Object(Article), false, true)
#6 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Hooks.php(158): call_user_func_array(Array, Array)
#7 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Article.php(919): wfRunHooks('ArticleViewHead...', Array)
#8 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Wiki.php(501): Article->view()
#9 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Wiki.php(69): MediaWiki->performAction(Object(OutputPage), Object(Article), Object(Title), Object(User), Object(WebRequest))
#10 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\index.php(115): MediaWiki->performRequestForTitle(Object(Title), Object(Article), Object(OutputPage), Object(User), Object(WebRequest))
#11 {main}

Exception caught inside exception handler: exception 'MWException' in C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\GlobalFunctions.php:983
Stack trace:
#0 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\parser\ParserCache.php(175): wfDebugDieBacktrace()
#1 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedRevs.class.php(809): ParserCache->save(Object(ParserOutput), Object(FlaggedArticle), Object(User))
#2 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedArticleView.php(1071): FlaggedRevs::stableVersionIsSynced(Object(FlaggedRevision), Object(FlaggedArticle))
#3 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedRevs.hooks.php(1632): FlaggedArticleView->setViewTabs(Object(SkinMonoBook), Array)
#4 [internal function]: FlaggedRevsHooks::setActionTabs(Object(SkinMonoBook), Array)
#5 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Hooks.php(158): call_user_func_array(Array, Array)
#6 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\SkinTemplate.php(837): wfRunHooks('SkinTemplateTab...', Array)
#7 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\SkinTemplate.php(464): SkinTemplate->buildContentActionUrls()
#8 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\OutputPage.php(1670): SkinTemplate->outputPage(Object(OutputPage))
#9 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Exception.php(188): OutputPage->output()
#10 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Exception.php(218): MWException->reportHTML()
#11 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Exception.php(321): MWException->report()
#12 C:\Program Files (x86)\Webserver\Apache\htdocs\small\wiki\includes\Exception.php(389): wfReportException(Object(MWException))
#13 [internal function]: wfExceptionHandler(Object(MWException))
#14 {main}

This is a FlaggedRevs issue, taking it. I can't replicate that exact stack trace (did you also update FlaggedRevs to r72881?)

I may have fixed it in r72896, can you please check?

The same error after update all used extensions.

If you are really running HEAD, the following is impossible:

#1 C:\Program Files
(x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedRevs.class.php(809):
ParserCache->save(Object(ParserOutput), Object(FlaggedArticle), Object(User))
#2 C:\Program Files
(x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedArticleView.php(1071):
FlaggedRevs::stableVersionIsSynced(Object(FlaggedRevision),
Object(FlaggedArticle))
#3 C:\Program Files
(x86)\Webserver\Apache\htdocs\small\wiki\extensions\FlaggedRevs\FlaggedRevs.hooks.php(1632):
FlaggedArticleView->setViewTabs(Object(SkinMonoBook), Array)

stableVersionIsSynced() isn't part of the FlaggedRevs class, it's part of FlaggedArticle (which appears nowhere in the stack trace). Even if that weren't the problem, ParserCache::save() isn't called from stableVersionIsSynced() at all. The only place it *is* called is RevisionReviewForm::buildQuickReview(), which is what I fixed in r72896.

I think you might have a configuration problem (make sure you're really using the updated copy of FlaggedRevs), as I cannot find this in trunk.

With a new checkout it works now correctly. Thank you for the help!