15:10 <GH> [Principia] pleroy commented on issue #1552: This looks like a race condition corrupting data: at the same microsecond we have (1) parts being added to some pile-ups, presumably on the main thread (15076) and (2) a pile-up being integrated on a thread of the pool (16544). This is unlikely to work because changing the composition of a pile-up is not protected. It would be good to understand what's happening in the C# side that causes this situation. ht