Can’t add files to MS Briefcase?

When I try to add a Quickbooks file to MS Briefcase I suddenly get this error after this process had been working perfectly for years:

“The files cannot be added to the Briefcase because it is a read-only disk or share. Make the Briefcase writable, then click Update All to create the files.”

I’ve tried to add the new file both over the network and even copied and pasted on my desktop and still get the error. I’ve followed the directions in the error and it still won’t work.

Does anyone have any ideas???

Thanks,
Lizz