Forum Discussion
Solved
Exchange Server error in '/owa' application
ASSERT: HMACProvider.GetCertificates:protectionCertificates.Length<1 Description: An unhandled exception occurred during the execution of the current web request. Please review the stack tr...
- Ok i found solution. Use this to create new certificate https://docs.microsoft.com/en-us/exchange/troubleshoot/administration/cannot-access-owa-or-ecp-if-oauth-expired
And after creating the certificate you must wait like a hour or more for changes work. Restart dont change the wait time 🙂
Nikolas_Athanasakis This solution worked for me with Exchange 2016 CU20. After installing several security updates today I experienced the same problem. I followed the instructions in the link and after restarting the two WebAppPools, OWA and ECP started working immediately. Thanks!