This is a error that keeps popping up for me when playing this game during the beginning of Episode 4 and crashes the game.
What happened was the idiots at Tose or Capcom decided that their PC port needed to be a 32-bit executable. The game can't go over 2 GB of RAM without crashing, and Revelations starts up with roughly 1.4GB of memory. This 32-bit memory error is a hard limitation of software that can be read below. A famous example of this happening is the 3D Fallout games regularly needing an extended memory patch to not crash because of this error.
wiki dot tesnexus dot com/index dot php/2-4GB_game_memory_limits_and_solutions
There's 2 solutions.
1. Set the graphical settings to LOW and\or a smaller resolution. 2. Use a 4GB tool and a cracked Executable. The reason why you need the ceraked executable is that Revelations won't start normally with the fix applied.
Both of these are not ideal at all, but Revelations is hard coded unless someone makes a good fix.