We've confirmed that all systems are back to normal with no customer impact as of 04/25, 02:30 UTC. Our logs show the incident started on 04/23, 21:50 UTC and that during 16 hours and 40 minutes that it took to resolve the issue some customers would have experienced issues while updating the availability web tests.
Root Cause: The failure was due to latest configuration
changes in one of our dependent platform services.
Incident Timeline: 16 Hours & 40 minutes - 04/23, 21:50 UTC through 04/25, 02:30 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.
We are aware of this issues with Application Insights. Our customers will experience issues with updating their availability web tests. This bug doesn't impact the functionality of currently running tests but interferes with customer's ability to update them, as per our telemetry, this incident started on 04/23/2018. We have root caused the issue and it is in the process of deploying a fix to resolve this.
Next Update: Before 04/25/2018, 02:30 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any inconvenience.