I'm working on a drawing and getting a persistent error message. When I double-click an equipment block to assign it the database, I get a message saying, "Nullable object must have a value" . There's no indication of what this means or what I'm supposed to do about it. This only seems to be happening with one specific type of equipment (Sony BRU-H700 camera controller) and only on one specific page (page 3). All 8 of the controllers on page 3 have this problem, but the 16 other controllers on pages 1 and 2 do not. Also, non of the other blocks in the project are having this problem. This began after spending several weeks building pages 1 and 2. I'm running version 8.0.1.1379.