Some bugs were addressed in this minor update of the original Multi game file archive editor MultiEx Commander. Also, donations required to obtain it go down to 5 euros! Check http://multiex.xentax.com. The readme says:
MultiEx Commander 4.5.1 Release Candidate 1.1 (Alpha) README.TXT
* Bugfix: (re)Compression of files as needed was failing.
* Bugfix: Browsing for files in left Mex Editor window was failing.
* Bugfix: Failure of decompression of files left some other files open, causing mayhem.
* Bugfix: Failed compression on files when user opted for extraction anyway would not work.
* Textual changes
Important note: You must at all times run MultiEx Commander as administrator. Make sure you set this in the short-cut accordingly.
If you do not run MultiEx Commander as admin, problems with file management may arise, causing the program to run ashore.
(C) 1997-1998 SadCom Ltd.
(C) 1999-2003 XeNTaX
(C) 2003-2004 XeNTaX/GNU Public License
(C) 2005 XeNTaX
(C) 2006-2013 The Xentax Foundation