Thread:Project:Support desk/Open .htaccess files in MW19.9/reply (3)

You can rename the folder and try, but the folder contains tests not for testing your MediaWiki installation, but for testing the MediaWiki source code itself. It is useful during development of the MediaWiki software, but as an end user you should not have to bother this folder at all. I would expect it not to be used - in fact I would even consider it a bug, if source code tests, which are made for development, were used during production usage.