After you upgrade to Microsoft Exchange Server 2016 CU7, you may notice that the Exchange mailbox transport delivery service is unable to start. Additionally, transport service (edgetransport.exe) crashes and returns the following error message:
ID: 4999
Level: Error
Source: MSExchange Common
Message: Watson report about to be sent for process id: xxxxx, with parameters: E12IIS, c-RTL-AMD64, 15.01.1261.035, edgetransport, mscorlib, M.W.RegistryKey.CreateSubKeyInternal, System.UnauthorizedAccessException