Windows restart sometimes required

Since 13.9.4 , Dopus (I believe) has triggered "restart windows" dialog at least 2 times

When doing which actions?

What makes you think Opus is showing the dialog and not something else?

The problem only started after installing this version

And I have seen the application fade and hang

If Opus is hanging, you can send us process snapshots if you want us to investigate.

But that would not cause Windows to ask you to reboot it, and whatever actually is causing that may be the underlying problem.