[Help]Wipes Fail both CWM and TWRP

I've been struggling with getting a ROM properly working, and it looks like because both TWRP and CWM aren't wiping properly. I looked up how to properly do a wipe, so I went into TWRP 2.7.0.1, Advanced Wipe and selected

-Dalvik Cache
-System
-Cache
-Data

The main error I get is this error and the wipe fails:

E:Unable to mount '/system'
E:Unable to mount '/cache'
E:Unable to mount '/modem'

So I tried to mount them manually, but it wont let me select those partitions.

I thought it was TWRP, but CWM 6.0.1.0 does the same thing because of the mount problem. I've already unbricked/went back to stock 3 times using RSD Lite 6.1.5. These errors are preventing me from restoring both backups I have from internal and external SDs. I've also tried go through FASTBOOT by using this command:
-fastboot erase system

But then it tells "permission denied". I'm using Windows 8.1 and changed the permissions in my fastboot folder. So now I only have access to fastboot or recovery.

Another thing i've noticed is that sometimes TWRP would crash and restart in the middle of a restore or wipe. I reverted to 2.7.0.0, this would still happen.

I've searched and searched but can't find anything to help with my issue. Like i've said before, I already returned it to stock rom 4.1.2 three times. What else can I do to properly wipe so I can flash a rom without any problems?


[RESOLVED]
For those who might have the same problem, i'm leaving the post as is. Here's what I did:
-Went into FASTBOOT and loaded an older version of TWRP. In this case, I flashed version 2.3.3.1(in other cases, I've had to use 2.2.2.2)
-Did a Wipe/Factory Reset(Do it 3 times to be safe)
-Dalvik/Cache Wipe(3X)
-System Wipe(3X)
-Reboot to FASTBOOT and flash back to the newest version of TWRP(2.7.0.1)
-Flash your ROM and make sure to Flash the correct compatible gapps
-Voila, everything should be good to go

xavi96end said:

The fix you have here worked for me, so thank you. however, i feel like we were both lucky to get this to work, and i doubt that we could recreate the issue exactly and fix this once again, for every time i try and flash a rom i encounter mounting errors everywhere, and they seem to be completely random. jumping from mounting /data, to /system, and even internal storage. this; on both twrp and cwm.
nonetheless, this post was of great help. i really appreciate you taking your time to edit the post. thank you again

Click to expand...

Click to collapse

I'm glad it was of some use to you guys, I spent about 3 days with a soft bricked phone because I couldn't find anything useful on why ALL the ROMs I flashed would be so buggy. Of course it was because the recoveries I werent wiping all the way. Anyway, I recently had a less serious and related issue with wiping again, and went to an even older version of TWRP 2.2.2.2. I'm really not sure why it happens, but it gets the job done.