I am getting this error with a subsequent crash, but I checked and I have no modifications to the view being performed on background thread. I even checked if the app was active before doing them. How may I track better the part of the code presenting the problem?
For some reason the issue does not seem to happen any longer. My feeling is that the error happens not only when some foreground object is moved in a background thread, but also when they are moved while the app itself is in background like when they are modified from the Watch app. Now I am verifying the state of the app is active before modifying the UI objects