Webi Doc prompts for query context but cannot select a context because 'OK' button is greyed out.

Using Business Objects 4.2 SP2. One of our universes has a couple of contexts built into it. When designing a report in Webi, when I go to run the query, I get prompted to select the appropriate context. However, the "OK" button is greyed out so no matter what I select I cannot proceed. Can't find info on this issue anywhere.