Cannot use the briefcase

I cannot add files to my briefcase on my laptop from my desktop computer.
Everything until recently was working fine but then I deleted an old user
account on the desktop. Now the briefcase refuses to update and I cannot
start a new one either. The message I receive when trying to update or add
files is that "the source file cannot be opened, please check it is
accessible and try again"

All files are shared and I have full access to them all from anywhere else
on the network. It is just the briefcase that refuses to work.

When I deleted the old user account on the desktop it warned me that I would
no longer be able to share the files and was this okay. I said "Yes" because
I didn't realise it was going to stop other user's data from being accessed,
which it hasn't except for the briefcase. Are there some permissions that
need to be reset somewhere. I cannot work out why I have full access to all
of the files I want to update/add to the briefcase from anywhere except the
briefcase.

Any help much appreciated.

I'm on XPHome by the way if that's relevant

--
FBB
Remember kids, don''t try this at home