With the recent Server Console changes we broke the ability to use an absolute path for your entities persist file from domain-server settings. A PR was just merged this morning that puts back this functionality.
If you have all along had an absolute path to the persist file in your domain-server settings, you may need to copy over the file from $APPDATA/$YOUR_ABSOLUTE_PATH to $YOUR_ABSOLUTE_PATH.
I believe the majority are not using absolute paths and should not experience any issues. Please let me know if not.