Verifying the integrity of the program

If DOpus cannot connect to GPSoft's web to verify the integrity of the program, then the program closes and it cannot be used.
Today I had to disable DOpus as the explorer replacement to at least be able to use Windows Explorer until GPSoft's web became available.

I would expect the software to continue working and not only to present 'Purchase', 'Download' or 'Close' as the options if it cannot validate the software.

That is incorrect. (You can use Opus without any internet connection at all. I do so regularly.) What makes you think it is the case?

If you are seeing the licence manager appear, it's probably because the evaluation period has actually expired (or something is wrong with the installation), not because a web server is down.

The reason why I think this is the case is that it happened on a day when there were routing issues from here (South Africa) to all eastern regions (Asia, Australia). While there were internet routing issues, DOpus could not be used. Once routing was corrected DOpus was again functioning as expected.

So, as far as evalution period is concerned, or something wrong with the installation, I don't think it was that.

Easy to test - disconnect your computer from the network and see if Opus works. You'll find it does.

If it didn't I'd be up s**t creek on my laptop.