This has just happened and on two machines. I mount Boxcryptor, open a folder, select several (or just one) file, CTRL+C and select the destination (an unencrypted USB stick), CTRL+V and I get …
Error 0x80070057 - The parameter is incorrect.
If I try to open anything that is encrypted, I get, "There was an error opening the file - the parameter is incorrect".
Currently ALL MY FILES are unreadable and totally useless.
I've already uninstalled Boxcryptor, restarted and reinstalled, but nothing works.
I'm dead in the water.
Your help is welcome.