I'm pretty sure this must be a local configuration issue. Somehow NCrunch has got itself into a state where clicking on the "Next" button in the "Parallel Test Execution" dialog (for "First Time Crunch") causes it to hang and then crash Visual Studio.
This occurs for _any_ project/solution but existing projects run fine.
If I copy the .ncrunchsolution and .ncrunchsolution.user files from another solution, or edit .ncrunchsolution to set SolutionConfigured to True, then Ncrunch can run.
The problem has persisted over several Ncrunch version upgrades.
It may also be relevant that it's impossible to exit the "First Time Crunch" flow once it's been started. Clicking on 'Cancel' or the exit button on the "New Solution To Crunch" dialog just results in the dialog closing and immediately reopening.
I've tried running as admin and also disabling extensions (Resharper, Ncrunch) but haven't yet found an obvious culprit.
I'm willing to bet something has gone wrong in your global config file. Delete the contents of C:\Users\USER\AppData\Roaming\NCrunch while the IDE is closed. This should reset your global configuration and hopefully resolve the issue.
Thanks Remco - that was a good tip. After some digging I realised the issue was this line where somehow I'd managed to insert a point instead of a comma between the 2&3. I notice the current configuration dialog prevents the user from getting this wrong but perhaps it was left older from a change in an earlier version or perhaps (less likely) I edited the config file manually some time in the past.