Default [Q] E:Unable to mount /cust

I was trying to install a new firmware on my Huawei Ascend P1, but I think I messed up a little.
Now, when I get into TWRP, I get the message:

Updating partition details...
E:Unable to mount /cust


I have other problems with the phone, and I think that this may be the cause of all of them...
Do you have any advice?