I've recently (today 8th Nov 2024) started having trouble copying files from my mobile phone to an external drive.
My Ubuntu Mate system was updated this morning and the mobile phone (Oneplus 9 pro) updated yesterday.
I regularly make copies of folders from my phones.
Today however I am receiving a message when the system catches a file with 'nomedia'. This then appears to stall the whole file copying process because if I click skip or skip all the message disappears but nothing continues to happen (I did wait for a considerable time before quitting the process manually using 'xkillall'.
I have tried a few times now without success. I get the message about 'nomedia'. Make a decision to skip and nothing happens. The file copying process just sits there. If I cancel instead then the file copying process greys out and I wait for resolution. The grey disappears but queued copying remains static. While typing this I received a message from what I perceived to be a stalled copying process (because there is no progress being shown on the textbox window progress bar) that states "There was an error reading the folder "Pictures". libmtp.error: could not get object handles. I quit from that message and the file copying process greys the windows again. I wait for the grey to clear (approx 1 minute). It doesn't look like the queued process is continuing with the last folder I have open. I press cancel. Nothing happens. I can close the window. I try to open a folder on Caja from my Mobile Phone. All file manager windows grey out. I wait. After about 1 minute the windows come back to life. While typing this they grey out again. I 'killall' on the file manager. No I don't as 'killall' has stopped executing. I need to restart to clear things... If anyone has any ideas about what may have happened in the recent update??? I will restore from previous to see if all is well. Watch this space.
A quick search for ubuntu file copy no media error android reveals that your situation is not unique and the question is popular enough over past years. Not unexpectedly, many answers are related to different underlying reasons and causes of the error. That makes it impossible to tell you anything definite enough.
Nevertheless, I'd propose that you try to use spare USB cable first. You know, elecstronics is all about contacts, after all...
If your phone is visible to your computer as a "drive", try doing a command-line copy/move from point to point with "--verbose" switch to get commentary of success/failure and save to a log, run that in background, then "tail -f" the log to see if you can spot the point of failure.
For me, you would create a list that is name-sorted so that you would have the reference of what is being done, then when it hangs, you know which file is causing the hang.