This new version of the ATRLS contains only one small bug fix. The bug in question occurs only at installation and only then very rarely. (It causes an improperly formated service registry entry, which prevents the ATRLS from starting.)
Existing users of version 5.0 do not need to upgrade. Should you need to move or reinstall version 5.0, we do recommend you switch to version 5.1. There should be no compatibility issues.
New installs should use version 5.1 rather than 5.0.
The version 5.1 upgrade is free to all licensees of version 5.0.