Help with 21 Bit Counter

[Amabilia]

Hello, for a final project I'm supposed to create a 21 bit binary counter that counts up to 111111110000111001000. The circuit itself seems to work but I keep getting an error saying its out of memory. I don't understand how it is running out of memory because when I check my task manager my RAM never breaks 40%. I've played with the TMAX a bunch but it keeps failing right when the 3rd most significant is about to change to 1. I know my circuit is wired backwards, but I can't imagine that would impact the memory? My post trigger samples are set to 3,000,000. I'm unsure what to do and any help would be greatly appreciated.