Cannot copy/move files within my LAN

[DroversDuck]

After using Total Commander for more than fifteen years, without a problem, things have suddenly gone pear-shaped; I cannot copy or move files to any memory location in my LAN.
I receive a message "Error: Cannot write e:\Thomas Cromwell.mpg! Please remove the write protection! The specified network name is no longer available."
Drive "e" is an NTFS-formatted USB drive that is not write-protected.
This problem confounds me and I am right out of ideas.
Can anyone suggest what might be causing this error condition?
Thanks - Neil

[beb]

...I cannot copy or move files to any memory location in my LAN.
I receive a message "Error: Cannot write e:\Thomas Cromwell.mpg! Please remove the write protection! The specified network name is no longer available."
Drive "e" is an NTFS-formatted USB drive that is not write-protected...

Your setup is unclear.
What is the network device your USB drive is connected to (another PC in the LAN, wi-fi router, etc)?
What is the connection/sharing method being used that your PC sees the USB as a local drive "e:" (network drive, etc)?
Does Windows Explorer behave the same?
What happens if you try to copy files not in the root of "e:\" but in a somewhat subfolder on it (let's say "e:\test")?

[DroversDuck]

Fair observation - I'll try to do better.
My home lan is predominantly ethernet cable, serving a couple of PCs, three NASs and a video recorder (that I use to record FTA television): there is no wireless involved in this problem at all. I am using one PC only to test the problem, connected to the NASs and the video recorder by ethernet, and to which is connected the USB drive (the "e" drive), that I referred to, physically plugged into the USB port on the PC's front panel.
I can ping all NASs and the video recorder from this PC.
The problem arises when I try to move or copy .mpg files from the recorder to the NASs or to a new location in the PC, either in the "C" drive or the USB "E" drive.
This has worked perfectly for more than ten years until the last month or so.
Now, I am able to report, beb, that as a result of your prodding me to be more descriptive and testing different aspects of my network, I seem to have found the problem, in a network setting for the video recorder. I do not know when or why that setting was changed. It seems that Commander was not able to access the files in the recorder but, what threw me was the message telling me that the destination was write-protected.
I feel somewhat ashamed for seeking help when I should have been more thorough before putting my hand up.
Thank you beb - my system is working well again and the problem was never anything to do with Total Commander, other than for the ambiguous error message.

[beb]

I feel somewhat ashamed for seeking help...

Nothing here to be ashamed of. You met an issue, asked for help, got some hints, rethought a point from where the issue may originate, and finally found your way to resolve the problem. This is how it works most of the time.
Great your problem has gone. Cheers.