We've found both the problems...
For easy and fast
fixing the 1st bug (described by sniggles) find the file Storm.scn. It is located in the folder
<YOUR MA FOLDER>\scenarios\campaign
e.g. if the folder where you installed Massive Assault is
C:\Program Files\Massive Assault
you need find the file
C:\Program Files\Massive Assault\scenarios\campaign\Storm.scn
Then, open the file in any text editor and change the line
UNIT, 9, ARTILLERYA, ALIENS, 56, 30
to:
;UNIT, 9, ARTILLERYA, ALIENS, 56, 30, i.e. just add a semicolon in the beginning of the line. That's all.
Fixing the 2nd bug, with the Noble Rust campaign, reported by ohSoDangerous - find the file
Arc of Fire.scn in the same folder as Storm.scn and comment (add a semicolon) the following lines:
UNIT, 4133, TANK, HUMANS, 22, 86
UNIT, 4134, TANK, HUMANS, 22, 86
UNIT, 4135, TANK, HUMANS, 22, 86
UNIT, 4136, TANK, HUMANS, 22, 86
Now you're ready to make games by your own hands
WARNING.The manipulations above lead to excluding several units from the scenarios and this can influence the possibility of passing the scenario. I just suggested the fastest way but the corrected scenarios need to be tested for balance and you may wait for upgrades... Have fun!