A few skins have autoloader errors and other related structure tests errors. We have to fix them all. T68926 added a job that runs Mediawiki structure tests to run on all the skins, some have been made voting but we still have to fix the following skins:
|BlueSpiceSkin||Fixed (depended on extension BlueSpiceFoundation|
|CustomPage||Depend on same name extension but it is a no/no T153050. Need renaming|
|Synagonism||https://gerrit.wikimedia.org/r/#/c/327535/ + a missing arrow-down-focus-icon.png|
They have the structure tests running but the result is ignored.