After updating to Mediawiki 1.27.1, I naively updated MobileFrontend from the Git master branch, but this produced the following error in the logs:
PHP Fatal error: Class 'ResourceLoaderUserStylesModule' not found in ../extensions/MobileFrontend/includes/modules/MobileUserStylesModule.php on line 11
And indeed, ResourceLoaderUserStylesModule was nowhere to be found. It was only added on July 26 to the Mediawiki core (and is not part of Mediawiki 1.27) and then referenced in MobileFrontend the same day. So yeah, one shoud pay close attention to release numbers and not mindlessly update straight from the master branch as I did :-) After checking out origin/REL1_27, the error went away and MobileFrontend works fine again! -- Evilninja (talk) 22:21, 23 August 2016 (UTC)