404- not found error in camunda bpm wildfly -7.11.0 while starting

Hi community,
I was new and training under camunda BPMN from past 1 week and using camunda modeler -4.2.0 v with camunda bpm wildfly- 7.11.0 v as a server. Till yesterday it worked well while I start the server. But today, it shows 404- not found. Could someone help me please!!

wildfly|690x159

Can you think of any changes you might have since it stopped working?
Also - have you considered upgrading the version since 7.11.0 is no longer supported. 7.15.0 is the newest version.

Hello there!
No, I have not made any changes and also no for upgrading the version sir!
But one of my friends told me to delete the extracted file and re-extract. So I did that and its working. I know this must not be the solution for this.
Thank you very much to reach me !