I noticed this error on one of my hosts today. After reading the full error message on the Events tab, and paying particular attention to the "Error Stack" section, it was obvious what the problem was.
"The configuration file of the virtual machine is corrupted". Well, that helps narrow things down, but what virtual machine is it?
After clicking on the host and going to the Related Objects -> Virtual Machines tab, the problem became even more clear.
This was a replica that we deleted last weekend. For whatever reason, vCenter didn't de-register it from the database when it was deleted. The VM no longer existed on the host. To fix the issue, just right click on the VM and click "Remove from Inventory".
After doing this DRS became healthy and all alarms were silenced. I hope this helps anyone experiencing this or a similar problem.