I just thought that I would post this in case it helps fixing problems for someone else.
I’ve had intermittent problems with uploading sketches to my boards with connection errors and fatal errors, but I have fixed it.
I had an expansion module which goes in a 5 /14 inch disk slot which has USB 3.0 plugs in it. The problem is that it’s about 8 years old and each USB plug has probably been used thousands of times, often just to charge things. The USB plugs however must suffer from wear and tear.
I’ve replaced the module with a new one and my problems with uploading sketches appears to have gone away.
