After almost 3 years of flawless service availability my app service came to a halt with the following event entry
.NET Runtime version 4.0.30319.0 - Loading profiler failed. Failed trying to receive from out of process a request to attach a profiler. HRESULT: 0x8007006d. Process ID (decimal): 60152. Message ID: [0x250d].
No code changes and no service changes were made so the solution was to restart the app service :rage: