I'm using the 10.1 M1 build, and I tried installing a font. It is the Ubuntu medium font. I don't know why, but it caused a bootloop. I restored /system from TWRP, and I installed the Ubuntu regular font. It booted just fine. What is the major difference between the two that makes the ROM break?
Phone: Verizon Samsung Galaxy SIII - Unlocked Bootloader
Previous Phone: Xperia Play (R800x) - Unlocked Bootloader
Tablet: Google Nexus 7 32GB Wifi-Only Unlocked Bootloader. (Half the LCD died... If you have a broken device with a functional LCD, please let me know.
If I'm posting something that has to do with my ROM/kernel, I'll provide them in the post. I'm quite fickle when it comes to these things.