New Post: Search.SearchTweets(searchParameter); suddenly returning null

I was successfully downloading tweets using Search.SearchTweets(searchParameter); but for some reason it now throws an null exception error.

I did make a search request with 100,000 results and I thought that could possibly result in a ban of some sort, but var tweets = Timeline.GetHomeTimeline(); does work and returns results and when I go to the application management screen I don't see any indication of a ban.

Any idea why this call is no longer working.

Thanks,
Carmen