"no network' when trying to copy files

Odd one:
Customer reports getting an error message when ‘trying to save a PNG file’

The message is
“There was a problem connecting to the server Contact your system administrator…”

Now, my code isnt trying to access the internet at that point.
192.168 .n.n looks like an IP address local to their own Wifi

The code being called does a copy of files from temp to
Might this be a Dropbox or Airdrop issue?

Maybe them saving to a network volume like one connected to an Airport extreme/express etc etc etc
Or another machine on their network

My thoughts too.
No response from user since I asked those questions, so its likely thats what it was…