I installed a plugin that is obviously broken and “crashed” my wiki with an error message. I can no longer access the extension manager, how can I uninstall the plugin anyway?

Plugins are installed in the lib/plugins/ directory. You can simply delete the plugin's directory and the plugin is “uninstalled”. The same is true for templates located in lib/tpl/.

To do so you need direct access to the wiki server's file system. For remote servers this can be achieved by SSH, FTP or your hoster's management panel.

Delete the directory, just renaming it might cause additional issues!