I imagine you're past this, but wanted to respond, if nothing, for other people that may run into this:
1. First, the 'problem ascertaining version information' message usually is due to either not being on a version that can upgrade to the version you're attempting to go to, or you're not upgrading to a high enough version of Dynamics GP based on the version you're already on. The duinstall.log it references is what we'd need to look at to verify.
At that point, Utilities wouldn't have touched the GP databases, so a backup or restore wouldn't usually fix or change anything.
2. It looks like you're upgrading to 18.5.1596 so it's normal that the GP Utilities window, right after the login window, would show this version, but the db_upgrade or DU000020 table would still be showing the old version, for PRODID 0, which is the core 'Microsoft Dynamics GP' module.
If you're still having issues, I'd open a support case so an engineer can assist in figuring out what we currently have and what needs to be done to get the databases upgraded.
Thanks
