Slow upload speed Thanks David. The upload speed to B2 is 9.4 Mbit/s. (Download is 154 Mbit/s.) I tested B2 speed with another computer on the same network and got 95 Mbit/s upload.
Backup gets stuck on one file and never progresses until I stop and start the backup again. File size is 38mb. I've let it run overnight and it remains on that file.
I don't see the Diagnostic option in the toolbar.