In Windows Explorer, navigate to C:\ProgramData\Acronis\MobileBackupServer\Conf and locate WRM.conf.
Right-click the file and select Properties.
Under Security, click Advanced.
In the Owner field (or on the Owner tab, the interface varies depending on your operating system) specify SYSTEM.
Make sure that SYSTEM and the user running Acronis True Image are specified in Groups or user names on the Security tab and have Full control. If not, add the missing user: click Edit -> in the opened dialog box enter the user name, check the Full control check box and click OK -> then click Apply and OK).
You can check which user is running Acronis True Image in the Task Manager. Open Task Manager. Under Processes, locate TrueImage.exe and note its user.