Running Win 7 Pro 64 bit with 32G, 30-40% memory usage, very stable workstation.
DO 11 ran flawlessly. Just upgraded to 12.6 (latest) and in two days has locked up hard twice. Once right-click on a zip file, once for no apparent reason. One was open on a network shared drive, the other on a CD drive, both had two listers horizontal.
When it locks, I cannot terminate even with Task Manager. Have to reboot to get rid of it.
If it was that on its own, I'd suspect a shell extension:
But that, and the other crash, suggests the underlying problem may be something low-level, like a driver or an antivirus scanner. As antivirus would potentially scan a .zip file when it was accessed to build the right-click menu, that makes it a possibility.
If it happens again, you should be able to create a dump file which we can use to see which components are involved in the problem:
While it's happening, please go to Task Manager, then the Details tab, right-click dopus.exe and select Create Dump File.
Do that 4 or 5 times, and it should create something like: