The website was woking well but suddenly its showing like this and even admin pannel isnt opening
Where are you hosting? Is it local? In the cloud? That was changed? What does the Umbraco log files say?
To be honest, without a log it’s really hard to determine the issue. Something is preventing the app from starting. Some things that come to mind:
- If you updated to a new major, the .NET version could be set wrong
- If you set the runtime mode of Umbraco to ‘production’, there could be prerequisits that are not fullfilled and Umbraco won’t boot.
- Changes in Program.cs?
See if the physical log files on the disk tell you something. Especially errors in runtime checks are hard to find.
Have you tried tapping the link in that screenshot and following the guide?
More reading is available here:
As Luuk mentions, this one is a bit difficult to give any advise on without knowing more about what you tried.
Do note that this error (all 500 errors) happen before Umbraco can even start, so there is nothing in the Umbraco logs, this is a server error and requires server logs.
Doesn’t Umbraco also produce a 500 ‘could not boot’ error when it’s running the runtime checks and one of those fails? Those are actually in the logs, but still cause a 500 (I think).