I am using Tracker with an on-line class of 13 students. The video files which I give them are relatively short mp4 of 1-2 MB. I have them upload their trk files to Canvas (the content delivery platform which we are using, similar to Blackboard). My computer is Windows 10. The students have various operating systems. We are all running Tracker 5.1.5.

Sometimes I can load their trk files without issue, but very often Tracker hangs while loading. The issue is not consistent. If I close Tracker using Task Manager, I can usually open the trk file after one or more attempts. It does not seem to depend on whether I ask Tracker to locate the original mp4.