I am also experiencing this issue while trying to install GL 9.2A 150903 on top of GL 9.0B on a synology NAS. Very interested to know how this situation developed or if anyone else has advice on the subject.

Users and administrators have full rights to the entire share that the softrak directory is in (according to both windows and the Diskstation manager that the NAS uses) but the installer complains about not being able to access the .CHM type files and moves on to getting stuck on wksetup.exe once they are removed prior to installation.

I've tried installing with the norton anti-virus completely disabled, switching from mapped drive locations to UNC locations, using the /linux parameter with the installation file, and all of those things combined but nothing has had any effect.