Tasks & Contexts / Open task. Window briefly appears then closes.

Pycharm 2016.3.2

Hi,
I want to integrated my pycharm project with YouTrack, but I'm having a bit of trouble with the Tasks in pycharm.

I click on the Tools menu, Tasks & Contexts, then Open Task.  But, very briefly I get a window flash up, but then disappear.

I've tried removing the server address, I've tried Switch task (which comes up, but when I choose Open Task, the same thing happens)

So unless I'm doing something daft (which is a distinct possibility!) I've tried all sorts.

Does anyone have anything I could try?  Maybe it's a corrupt piece of data somewhere, I've also tried it on different projects.

I'm running it on Linux Fedora 24, on Qubes.  Everything else runs great.

Much appreciate any help :-)

Mark.