Last Sunday one of our azure web apps went down for no obvious reason. There had been no code deployments for the past 5 days, the app was running fine on an S3 service level on a paid subscription. The only logical explanation I could come up was some VM being changed/upgraded underneath which caused our app to die.
After enabling the detailed error messages and logs through the stdout configuration in the web.config. I got to the following error:
"Could not load type 'System.Diagnostics.InjectedFunctionParent' from assembly 'System.Private.CoreLib'..."
Funny thing is we don't use such an assembly anywhere in our code...
We tried multiple solutions (re-deployment, scaling up and down the service plan, etc.) but the only one which worked was to delete the entire web app from azure and create it again...
Anyone bumped into a similar problem? How did you solve/prevent this?
Thanks in advance!