7-Zip is open source software. Most of the source code is under the GNU LGPL license. The unRAR code is under a mixed license: GNU LGPL + unRAR restrictions
Change log (9.32):
Some BUGs of 7-Zip 9.31 alpha were fixed:
- 7-Zip could not unpack some RAR archives
- 7-Zip File Manager could work incorrectly for unpacking from solid archives,
if archive was open in 7-Zip File Manager. Also 7-Zip File Manager could leave
some unpacked files in TEMP folder of Windows.
So look your TEMP folder and remove folders that have "7z" prefix in name.