I am having the same issue being discussed here: https://forums.plex.tv/discussion/245603/stop-sync-fails
This seems to be a bug - has this been reported? Here are the steps I follow to reproduce:
- Click Status >> Conversion
- Try removing an item by clicking the red cross on the right hand side
- A ‘Stop Syncing’ dialog appears.
- Click Remove. Nothing will happen, even if you wait for ages.
- Click Remove again. The text on the button gets replaced with a white spinning circle.
- Nothing happens, no matter how long you wait and the queued conversion item isn’t deleted.
Using Chrome v55 and PMS 1.3.3.3148-b38628e on Windows 10.