The last few days my Exchange server (Passive) starting with all these errors, I did an IISRESET and it worked for about 10 min and then the issues started again.
After this I was also seeing other strange events logged, OWA errors, IIS errors every 5 min, my event log went to around 5500 events in just an hour.
I then restarted the Microsoft Exchange Health Service and this kick started everything again. No errors reported after that. My event viewer started filling up with Information alerts like everything came back online 🙂
Hope it helps