We have a Mediawiki 1.34.4/PHP 7.2.24 installation at www.cryptopp.com. We are using Modern from GitHub, the REL1_34 branch. Attempting to load Modern results in:
Fatal error: Uncaught Error: Call to undefined method ModernTemplate::cactions() in /var/www/html/w/skins/Modern/SkinModern.php:75 Stack trace: #0 /var/www/html/w/includes/skins/SkinTemplate.php(217): ModernTemplate->execute() #1 /var/www/html/w/includes/OutputPage.php(2574): SkinTemplate->outputPage() #2 /var/www/html/w/includes/exception/MWExceptionRenderer.php(134): OutputPage->output() #3 /var/www/html/w/includes/exception/MWExceptionRenderer.php(53): MWExceptionRenderer::reportHTML(Object(Error)) #4 /var/www/html/w/includes/exception/MWExceptionHandler.php(121): MWExceptionRenderer::output(Object(Error), 2) #5 /var/www/html/w/includes/exception/MWExceptionHandler.php(195): MWExceptionHandler::report(Object(Error)) #6 /var/www/html/w/includes/exception/MWExceptionHandler.php(167): MWExceptionHandler::handleException(Object(Error)) #7 [internal function]: MWExceptionHandler::handleUncaughtException(Object(Error)) #8 {main} thrown in /var/www/html/w/skins/Modern/SkinModern.php on line 75
It looks like this has been going on for a couple of years now: Upgrade to 1.32 getting an internal error.