[Android Q&A, Help & Troubleshooting] Kinriso:
Recently I was asked to look at a Hudl 2 tablet for someone because Unfortunately, <app> has stopped working appears continually for various apps to the point where the tablet is unusable. It generally starts around fifteen minutes after boot, or almost immediately when connected to WiFi.

One of the first things I did was enable USB debugging and try see if logcat was of any help, since the issue seemed to affect most of the few installed apps. What I found is a little weird - it seems the device has gone read-only:

W/CatchMeIfYouCan( 1779): IOException
W/CatchMeIfYouCan( 1779): java.io.FileNotFoundException: /data/data/com.facebook.katana/app_cmiyc/--snip--: open failed: EROFS (Read-only file system)
...

E/DropBoxManagerService( 515): Can't write: system_server_wtf
E/DropBoxManagerService( 515): java.io.FileNotFoundException: /data/system/dropbox/drop72.tmp: open failed: EROFS (Read-only file system)
...

E/SQLiteDatabase( 515): Error inserting COL_TIMESTAMP=1449339690983 COL_EVENT_NAME=device.logs.message COL_JSON_DATA={"message":"Failed to open database '\/data\/data\/com.google.android.talk\/databases\/message_store.db'.","process":"SQLiteDatabase","timestamp":1449339690983,"severity":"E","eventName":"device.logs.message","processId":" 2388","sourceId":"63a914a45c666fd344ae04a0cfe24298"}
...

E/AndroidRuntime( 3944): Process: com.google.process.gapps, PID: 3944
E/AndroidRuntime( 3944): java.lang.RuntimeException: Unable to get provider com.google.android.gsf.gservices.GservicesProvider: android.database.sqlite.SQLiteException: not an error (code 0): Could not open the database in read/write mode.
...

E/DropBoxManagerService( 515): Can't write: system_app_crash
E/DropBoxManagerService( 515): java.io.FileNotFoundException: /data/system/dropbox/drop131.tmp: open failed: EROFS (Read-only file system)
...

These errors appear continually and fill mintty's scrollback buffer within a few seconds.

Given that the device is unrooted, I figured there's not much I can do to try fix the issue other than a factory reset. The factory reset from the bootloader seemed to have completed successfully having reportedly erased the relevant filesystems, yet when I booted the device back up it was the exact same as it was before. I then thought I could try rooting the device in case I could fix the problem. I followed a guide from MoDaCo (unable to link because I'm a new user), but when I try to flash the image through fastboot it hangs. After rebooting, it's again exactly the same.

Here's the output from adb shell mount:

rootfs / rootfs ro,relatime 0 0
tmpfs /dev tmpfs rw,seclabel,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,seclabel,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,seclabel,relatime 0 0
selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
none /sys/fs/cgroup tmpfs rw,seclabel,relatime,mode=750,gid=1000 0 0
tmpfs /mnt/secure tmpfs rw,seclabel,relatime,mode=700 0 0
tmpfs /mnt/asec tmpfs rw,seclabel,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,seclabel,relatime,mode=755,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
/dev/block/platform/intel/by-label/factory /factory ext4 rw,seclabel,nosuid,nodev,noatime,data=ordered 0 0
/dev/block/platform/intel/by-label/system /system ext4 ro,seclabel,noatime,data=ordered 0 0
/dev/block/platform/intel/by-label/cache /cache ext4 rw,seclabel,nosuid,nodev,noatime,data=ordered 0 0
/dev/block/platform/intel/by-label/config /config ext4 rw,seclabel,nosuid,nodev,noatime,data=ordered 0 0
/dev/block/platform/intel/by-label/data /data ext4 ro,seclabel,nosuid,nodev,noatime,discard,noauto_da_alloc,data=ordered 0 0
/dev/block/platform/intel/by-label/logs /logs ext4 rw,seclabel,nosuid,nodev,relatime,data=ordered 0 0
adb /dev/usb-ffs/adb functionfs rw,relatime 0 0
none /sys/kernel/debug debugfs rw,relatime,mode=755 0 0
/dev/fuse /mnt/shell/emulated fuse rw,nosuid,nodev,relatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw,relatime 0 0
tmpfs /mnt/libreg tmpfs rw,seclabel,noexec,noatime,size=4k,mode=700,gid=1003 0 0

Hardware issue?

I'm guessing this tablet is toast, but is there anything else I could try?