Hail, my viking brother, and welcome to the forum!
You should probably try running with either --log-level DEBUG
or -vv
to enable debug-mode output. This will show you a lot more info about everything. Too much for daily use as it is quite spammy, but it's very useful for diagnosing a spesific issue.
Not al lerror-messages can necessarily be very spesific however. Not so much a fault of rclone but rather that it in some cases has to rely on outside messages which are overly general.
I/O errors are usually not too cryptic though. Very often it's a consequence of asking hardware do something it is not psychically capable of. For example - it might happen if you asked rclone to copy something to a drive or cache that ran out of space, or had a filename that was too large or contained "illegal" characters that the destination filesystem could not accept.
If you can describe what you are doing when you get this error and also post your debug-log (or at least a good chunk of it showing the error) then we can probably figure this out
It also helps in general if you take the time to answer the basic questions the forum prompted you for. Your cloud service provider, your rclone version ect. Often such things are more relevant than you may think.