Oh well, too good to last, it has started crashing again.
For now I've gone back to 11.5, that seems to be that last stable version I can run 
I don't think anyone else is seeing crashes like that in 11.7. Let's see if the crashes start happening for you in 11.5. I suspect they will, since this is probably not the same problem everyone else was seeing (assuming 11.7 was installed and you rebooted at the end). If you do see crashes in 11.5 as well then the issue is likely a shell extension that has been installed/updated since things were stable. We can go over how to track that down if it turns out to be the case.
I'll keep you posted on how I get on with 11.5, but the crashes were occurring on a PC and a laptop that i have set aside and dedicated to trying to nail down what is causing it. Nothing else has been installed on the machines except Windows 7 on the desktop and windows 8.1 on the laptop, haven't even installed office, 7-zip, Anti-Virus, etc., I want to rule everything out.
Bizzarrely when the crashes started under 11.7, i got a the same message but a different result than under 11.6. DOpus would crash, try to restart and immediately crash again, and then completely fail to respond until i used the task manager to kill the dopus and dopusrt processes.
I'll let you know how I get on.
Quick update. Since installing 11.5 it has been running as sound as a pound.
I would try jumping direct to 11.7 (skipping 11.6) now, to see if that works.
If you're on a fast connection, it may also be worth re-downloading the installer, just in case: downloads page.