Hello @mg281,
In your viewport, please open the viewport options menu in the upper left and check to see if the “realtime” parameter is checked. Tilesets will not load if the viewport isn’t realtime.
Are you using a remote desktop software, by any chance? If so, please check out this thread for additional guidance.
If that is not the culprit, let me know and we’ll continue to troubleshoot.
-Alex