- do not use a PC to unpack the MUI archive
- do not store the files from the MUI archive on a PC storage medium
- do not use UnArc without Boingbag1 to unpack the MUI archive
If you do one of them, the requested file is lost and MUI cannot be installed. You have to copy the archive to your Amiga and then use either LhA or UnArc of BoingBag1 or higher to unpack it.