The Skype for Business Server Video Interop Server has encountered a major call completion problem with the Front End.
Calls to this Front End failed 5 times with failure final responses. Check other MOM alerts for more details.
If the failure is due to CALL_FAILURES_DUE_TO_UNEXPECTED_PROXY_INTERACTION, there is some internal issue with the Front End's link to the Skype for Business Server Video Interop Server (misconfiguration, load) that is causing it not to complete calls. Please consult the failure reports on the Monitoring Server for more details.