Overview
If you have set up the M-Files services manually to run as an account that is *not* Local System, after an upgrade you may notice that M-Files has been set back to running as Local System. This can break synchronization and other permissions related connections. Note: This behavior applies only to manual changes to the services, see the end of the article for the sustainable way to keep them running under a service account.
Solution
M-Files is always installed to run as a Local System account. Any time there is an update, it's going to revert back to being a Local System account. What is happening is that whenever M-Files updates on the server, it reverts to being run as a Local System account because it creates a new service for the new version, and the manual changes made to the old one are lost. The solution here is to perform planned upgrades by turning off automatic update on the server and then performing the upgrade manually during some pre-planned date and setting the system account after the upgrade. Relevant documentation:
If running M-Files under a service account is required, please see the following article: Setting M-Files Services to Use a Managed Service Account
