I am hoping someone can point me in the right direction ... My tablet was originally running CM11 and CWM internally.
I was also unable to install TWRP using the flashable zip. Same Error mentioned in post #2. Anyway, I was able to successfully flash TWRP using the "TWRP Manager" app by JMZ Software. For some reason, the official TWRP app kept failing as well.
Anyway. I booted into TWRP and chose to completely wipe everything. It happily did this, but it seems to have also wiped away the partition information from whatever mmc device is meant for /data. I am unable to mount internal storage. Fantastic.
Exposing the terminal in TWRP shows this in red:
Failed to mount '/data' (No such device)
The tablet seems to have some water damage that has messed up the sdcard slot, but works fine otherwise. I ran CM11 for several days before getting the bug to upgrade. Fixing my problem via booting to the sdcard is unfortunately NOT an option.
I do still have ADB access to the device. Here are the contents of /dev/block, followed by what is currently mounted on the device.
~ # ls -al /dev/block/
__bionic_open_tzdata: couldn't find any tzdata when looking for localtime!
__bionic_open_tzdata: couldn't find any tzdata when looking for GMT!
__bionic_open_tzdata: couldn't find any tzdata when looking for posixrules!
drwxr-xr-x 4 root root 820 Jan 1 00:16 .
drwxr-xr-x 11 root root 2620 Jan 1 00:16 ..
drwxr-xr-x 4 root root 80 Jan 1 00:16 bootdevice
brw------- 1 root root 7, 0 Jan 1 00:16 loop0
brw------- 1 root root 7, 1 Jan 1 00:16 loop1
brw------- 1 root root 7, 2 Jan 1 00:16 loop2
brw------- 1 root root 7, 3 Jan 1 00:16 loop3
brw------- 1 root root 7, 4 Jan 1 00:16 loop4
brw------- 1 root root 7, 5 Jan 1 00:16 loop5
brw------- 1 root root 7, 6 Jan 1 00:16 loop6
brw------- 1 root root 7, 7 Jan 1 00:16 loop7
brw------- 1 root root 179, 0 Jan 1 00:16 mmcblk0
brw------- 1 root root 179, 8 Jan 1 00:16 mmcblk0boot0
brw------- 1 root root 179, 16 Jan 1 00:16 mmcblk0boot1
brw------- 1 root root 179, 1 Jan 1 00:16 mmcblk0p1
brw------- 1 root root 259, 2 Jan 1 00:16 mmcblk0p10
brw------- 1 root root 179, 2 Jan 1 00:16 mmcblk0p2
brw------- 1 root root 179, 3 Jan 1 00:16 mmcblk0p3
brw------- 1 root root 179, 4 Jan 1 00:16 mmcblk0p4
brw------- 1 root root 179, 5 Jan 1 00:16 mmcblk0p5
brw------- 1 root root 179, 6 Jan 1 00:16 mmcblk0p6
brw------- 1 root root 179, 7 Jan 1 00:16 mmcblk0p7
brw------- 1 root root 259, 0 Jan 1 00:16 mmcblk0p8
brw------- 1 root root 259, 1 Jan 1 00:17 mmcblk0p9
drwxr-xr-x 3 root root 60 Jan 1 00:16 platform
brw------- 1 root root 1, 0 Jan 1 00:16 ram0
brw------- 1 root root 1, 1 Jan 1 00:16 ram1
brw------- 1 root root 1, 10 Jan 1 00:16 ram10
brw------- 1 root root 1, 11 Jan 1 00:16 ram11
brw------- 1 root root 1, 12 Jan 1 00:16 ram12
brw------- 1 root root 1, 13 Jan 1 00:16 ram13
brw------- 1 root root 1, 14 Jan 1 00:16 ram14
brw------- 1 root root 1, 15 Jan 1 00:16 ram15
brw------- 1 root root 1, 2 Jan 1 00:16 ram2
brw------- 1 root root 1, 3 Jan 1 00:16 ram3
brw------- 1 root root 1, 4 Jan 1 00:16 ram4
brw------- 1 root root 1, 5 Jan 1 00:16 ram5
brw------- 1 root root 1, 6 Jan 1 00:16 ram6
brw------- 1 root root 1, 7 Jan 1 00:16 ram7
brw------- 1 root root 1, 8 Jan 1 00:16 ram8
brw------- 1 root root 1, 9 Jan 1 00:16 ram9
~ # mount
rootfs on / type rootfs (rw)
tmpfs on /dev type tmpfs (rw,nosuid,relatime,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
tmpfs on /tmp type tmpfs (rw,relatime)
/dev/block/mmcblk0p8 on /system type ext4 (rw,relatime,barrier=1,data=ordered)
/dev/block/mmcblk0p9 on /cache type ext4 (rw,relatime,barrier=1,data=ordered)