Just checked the files. You screwed up the animations.rfa configuration. If this is supposed to run on top of BF1942 and DC, you must put all new animations into a copy of the DC's animationsMod INC file or at the least copy over all the DC con and INC files from animations and then add the new weapon stuff to them. You simply made new files that included only the P-90.
Since this meant that all previous states were erased, pretty much all animations for all the weapons, soldiers, and flags broke!
So you gotta include the full content of the CON files you are modifying! So make sure all the stuff from DC is in the con files you changed. Don't worry about BF1942's stuff, DC mod already included those in the files!