Exception encountered, of type &quot;Error&quot;<br />
[55b0efa1] /load.php?debug=false&amp;lang=de&amp;modules=mediawiki.action.history.diff%7Cmediawiki.legacy.commonPrint%2Cshared%7Cmediawiki.sectionAnchor%7Cmediawiki.skinning.interface%7Cskins.vector.styles&amp;only=styles&amp;skin=vector   Error from line 653 of /mnt/web107/e3/91/5564191/htdocs/includes/exception/MWExceptionHandler.php: Class 'FormatJson' not found<br />
Backtrace:<br />
#0 /mnt/web107/e3/91/5564191/htdocs/includes/exception/MWExceptionHandler.php(241): MWExceptionHandler::logError()<br />
#1 /mnt/web107/e3/91/5564191/htdocs/includes/AutoLoader.php(90): MWExceptionHandler::handleError()<br />
#2 /mnt/web107/e3/91/5564191/htdocs/includes/AutoLoader.php(90): require()<br />
#3 [internal function]: AutoLoader::autoload()<br />
#4 /mnt/web107/e3/91/5564191/htdocs/includes/resourceloader/ResourceLoader.php(125): spl_autoload_call()<br />
#5 /mnt/web107/e3/91/5564191/htdocs/includes/resourceloader/ResourceLoader.php(684): ResourceLoader-&gt;preloadModuleInfo()<br />
#6 /mnt/web107/e3/91/5564191/htdocs/load.php(47): ResourceLoader-&gt;respond()<br />
#7 {main}<br />