RoboHelp 10 crashes when applying conditional build tags

Up until today, I have never had any problem applying conditional build tags. Suddenly today, when I select a paragraph, right-click, and select Apply Conditional Build tags, RoboHelp crashes. I tried it from Format menu as well with the same result. If no paragraph is selected and I select Format > Apply Conditional Build Tags, the list is empty. If I select View > Pods > Conditional Build Tags, all my tags are there. I have tried this in several different help projects, all with the same result, so it's not project specific.

This is a big problem that needs to be solved asap. Anyone have any ideas?

Thanks,

Natasha