[Samsung Galaxy J5 Guides, News, & Discussion] Rizzed:
I'm just going to leave this here in case anyone of you encounters this problem after modifying files in the system or after flashing custom ROMs. Do note that this fix does not remove the error, but instead bypasses it (for those without EFS backup) and enables the system to boot up normally (installs SuperSU as well). Also, as this requires the use of Odin, devices running MacOS or OSX are not supported.

An alternative (and easier) method has been discovered (refer to post #4 for more details)

Prerequisites:

1) TWRP recovery (https://drive.google.com/open?id=0B6QXDUz9wzc9YWcyZklybmZLc0k)

2) dm-verity bypass (https://drive.google.com/open?id=0B6QXDUz9wzc9Wk1ra0hKYVJtT1k)

3) Odin (https://drive.google.com/open?id=0B6QXDUz9wzc9c3BxYzdBNXhvbnc)

Steps (please follow the steps accordingly in order):

1)

Place your phone in D/L mode

- Ensure device is fully turned off by pressing the volume down and power button

- Hold the volume down, home, and power button until a blue warning screen appears

- Press once on the volume up button

- Connect your device to your computer

2)

Flash TWRP onto your device

- Open Odin and click on the "AP" tab, and then directing to the location of the TWRP recovery (TWRP_3.0.2.tar)

- Click on the "Options" tab and untick the option "Auto Reboot" [DO NOT TICK ANYTHING ELSE]

- Click on "Start" until Odin says "PASS!"

3)

Reboot device into TWRP and flash the bypass zip

- Hold the volume down and power down button until the screen turns off

- Then, hold the volume up, home, and power button until "Set Warranty Bit : recovery" appears at the top of the screen

- Click on "Advanced", followed by "ADB Sideload" and ensure that "Wipe Dalvik Cache" and "Wipe Cache" is ticked, then swipe the bar at the bottom to start sideload

- Using the command prompt, type "adb sideload dm-verity bypass.zip" and wait till it completes

- Click on "Reboot System" after it completes, and your system should be able to boot

Possible errors which you may have encountered:

1) Odin does not detect my device

-- [You will need to install the device driver]

> Download the driver at https://drive.google.com/open?id=0B6QXDUz9wzc9LU9FclQ5WjNWRFk and install it.

2) My device does not boot into recovery after flashing via Odin

-- [System was trying to boot instead of recovery and had ignored the custom recovery after that]

> Go back to step 1) and repeat again

What is ADB and where can I get it?

> The installer is available for download at https://drive.google.com/open?id=0B0MKgCbUM0itNVB1elljU2NPR0k

> Run the installer and type "Y" for every prompt

> Open the command prompt (On your keyboard, press the windows key followed by the "R" key, then type "cmd" in the window and press enter

> Type "cd C:\adb" and you may continue with the steps (do note that C: is the mounted letter of your root drive which may be different from yours)

"* cannot read 'dm-verity bypass.zip *" appears after I entered the command

-- [ADB cannot read the file as the file cannot be found]

> Copy the dm-verity bypass.zip into your ADB folder, or after typing "adb sideload ", drag the dm-verity bypass.zip into your command prompt window and then pressing enter.

Do notify me immediately if there are any errors. Thank you and good luck!

Thanks to [MENTION=7716560]KingWilliams[/MENTION] for the dm-verity bypass zip which was present in one of your ROMs.