This problem is usually caused by the user lacking permissions. You can give the user which runs the Exchange Server Toolbox Service access rights to the folders or you can reinstall the service and create a new user. For the latter solution please refer to this article: https://knowledgebase.jam-software.com/7481
You can find backups of your blacklist and whitelist settings in the following folder: C:\Windows\System32\config\systemprofile\.spamassassin\backup
In case these folders are empty or missing you can try to restore the file user_prefs from one of the following directories using a filesystem backup:
This error occurs when the Exchange Server Toolbox could not access the Active Directory. You can manually create the Group Account instead.
Members of this group have superuser rights to the archive and can find every email using the archive search.
Please reinstall the Exchange Server Toolbox Service and create a new user during the installation. To do so please follow these steps:
You can find the file ESTInstall in the following folder:
C:\Program Files (x86)\JAM Software\Exchange Server Toolbox\bin
To use the argument /force you can start the installation with the command line tool. Start cmd and enter the following commands:
Alternatively, you can create a shortcut of ESTInstall. Right-click it and add /force at the end of "Target".