Hi i am constantly trying to login in my app but every time i get this error"Server not Found" and also in the console i get OSGI event handler warning "EventAdmin: Exception during event dispatch [org.osgi.service.event.Event [topic=com/mendix/events/runtime/beforeRunning] | [org.osgi.service.event.EventHandler] | Bundle(webui )] (bundle: webui, service: [org.osgi.service.event.EventHandler])" and error "404 - file not found for file" I have recently upgrade my app from 4.5 to 5.12 and replaced collapsible panel from group box and snippet combination.
The upgrade is probably the cause of your error. Did you migrate from 4.5 to 5.12 instantly?
Normally it's advised to first upgrade to the 'latest' release of Mendix 4 before upgrading to the 5 version.
I suggest upgrading to 4.8 (I think) first, before migrating to 5.12