autodesk inventor 2015 loads then disappears

On some of my colleagues' machines it doesn't even flash but is immediately hidden behind. On my machine the popup briefly flashes on the screen before disappearing. The same problem occurs if I have an assembly open, and I then right-click on any subassembly in the Inventor window and select 'open'.

If you then hit Alt-tab or the Windows key you see that there is the same message in an Inventor popup behind asking to check out all the components of that assembly that need to update. However if I double-click on an assembly file in the Vault window I get the same Vault popup asking if I want to check the assembly file out and click 'yes', but then in the Inventor window a new tab opens at the bottom of the screen for that assembly but the assembly does not open and Inventor appears frozen. Do you want to check it out now?' I select 'yes', and the part opens, checked out. The most consistent way to see the issue is as follows: If I have Inventor and a Vault client window open and I double-click on a part file in the Vault window I get the popup, in the Vault window, 'File xxx is not checked out.

The issue occurs any time we open a Vault assembly, by any method, whose components want to update themselves and so want to be checked out to allow the update.

I have noticed more details of what happens:

Autodesk inventor 2015 loads then disappears