Hexen went through a few technical changes from 1.0 to 1.1, one of
which includes moving text strings (left to the engine itself in 1.0)
to the IWAD.  This actually makes playing Hexen 1.0 problematic on
source ports, where only 1.1 is well-supported.

“Beta” is a release made only on the warez scene, leaked from Raven
before the game was finished.  It should only be played with the
equivalent engine files (see the vanilla-engine directory).  Being
released to the world only via warez, there is no legitimate reason
you should need to upgrade from it to a newer version of Hexen, thus
the patch here is to only go backwards from 1.1.

If unsure of which version you have, refer to these sha1 hashes:
ae797f5fdce845be24a7a24dd5bfc3e762a17bbe  hexen_beta.wad
ac129c4331bf26f0f080c4a56aaa40d64969c98a  hexen_1.0.wad
4b53832f0733c1e29e5f1de2428e5475e891af29  hexen_1.1.wad
4343fbe5aef905ef6d077a1517a50c919e5cc906  hexen_mac.wad