mobile

I've had Android Revolution HD installed on my phone for a while and decided to update it. I wiped the usual and went into aroma to continue the installation, but it got stuck at "formatting partitions" which then I turned off my phone and rebooted it. It was soft bricked so I thought okay no problem, wiped again, and installed the previous version of Android Revolution HD that I had previously, however to no affect. Meanwhile in TWRP it also says "E: Unable to mount '/system' "'

EDIT: I have TWRP v2.8.4.0 and in "Mount", system is not checked.