Router not working after login

[WebmasterCollege]

New issue:
Managed to switch to on / off mode using the config file and uncommenting $CFG->urlrewriteclass = '\local_cleanurls\url_rewriter'; Now: switching "on" everything seems to work untill I go to login. Than everything goes back to "Invalid URL". Tried with cleaning cache but did not help.
So my workaround at the moment is setting on "off" when I use in the classroom and when editing, and setting on "on" when not using as teaching resource. Problem is: I need to use the site mainly as teaching resource......