Hi Alexey,
Thanks. I've been able to open the *.psz file in 7zip and can see the associated project files (*.oct, *.xml, image masks and projection files, etc.). I tried rebuilding the *.psz from a *.zip format using Disk internals Zip Repair. No change, it still loads to about 75% and then... "Can't open file".
I also checked my EXIF/Software parameters for unicode symbols in the xml, as was the issue for other forum users, but I couldn't fine any cases where that might be the problem...
What can I try next?
Thanks!