This happened to me recently while I was editing some information for mobs in crevice for testing purposes. After I was done editing (took me a long grueling 30 minutes) I tried to save my pack.d04 but was given the error "Invalid txt" or something to that extent, and it seemed that I was unable to save my edited pack.d04 anywhere on my computer.
So I finally decided to close the file in winhex and just start all over, but to my amazement, everything in my pack.d04 looked different.
This is what the contents of my pack.d04 looked like.
I was puzzled by this, but thankfully I keep about 4 backups in random places on my PC to prevent losing my edited pack.d04. However, all my pack.d04 files, regardless of where I saved them, ended up looking the same. So now every single pack.d04 file on my PC looks like this (corrupted text?) and I am no longer able to edit any values.
I'd like to point out however, that even though my hacked pack.d04 and my backup pack.d04 look like this, they both work they way they are supposed to if I replace them in the data folder.
I tried reinstalling 2moons but the freshly installed pack.d04 also looked the same. This leads me to believe that this could also be a problem with my version of winhex. Has anyone encountered this problem before? And if so, do you know of any fixes?