Acronis Active Protection stops on its own.
"Application error" event about anti_ransomware_service.exe is recorded in Windows Application event log (open Windows Start menu, type eventvwr.msc, press Enter, navigate to Windows Logs - Application).
Known issue with the software. The application crash occurs when the software is unable to parse configuration files.
This issue has been fixed in Acronis True Image 2020 Update 3 (Build 25700), please update to the latest build.
In case you cannot install the latest update for some reason, as a workaround the issue can be fixed by replacing Acronis Active Protection configuration files with default ones.