This issue is related with the registry option "nShowMSIPCOptions", when versions of sharing app are newer than v. 1.0.1770.0, that are installed with RightsWATCH from version 126.96.36.199 going forward.
The problem is that we are removing a registry key that is essential for sharing app to instantiate and start its execution (HKEY_CLASSES_ROOT\AllFilesystemObjects\shell\Microsoft.RMSSharing.ProtectWithRMS), so when it is not found a recovery process starts that resembles a new installation.
This is only happening on very specific situations.
To fix this, for now, we advise that RightsWATCH should be installed with the "nShowMSIPCOptions" option set to 1 on the rw-config.ini file.
Additionaly, the Sysadmin of the client can go to the following registry key: "HKEY_CLASSES_ROOT\AllFilesystemObjects\shell\Microsoft.RMSSharing.ProtectWithRMS" and add a new String value with name "LegacyDisable" and value "Enabled".
This should be enough for the "Protect with RMS" shortcut on the shell extension to not appear anymore