Hmm, I would suggest trying to
install another official RON, via
odin,
and then rooting.
Since you have an
XX (multi-css)
ROM, and I presume your phone is from
Netherlands,
you maybe can try and flash the ROM I am on (
link here)
or another unlocked ROM from any of this country`s Austria, Belgium, France, Germany, Hungary, Romania, Italy, Spain, United Kingdom.
The
take-away here being for the
ROM to have multi CSC, so you
don`t lose your sales codes.
This is the link for your current ROM, untouched:
http://www.sammobile.com/firmwares/1/?model=SM-N9005&pcode=PHN#firmware
LE:
If you decide to try this, please come back and post your results. This should get you back to official status.
Please note that this will wipe your device.
Also you may try to do a factory reset, and see if you get rid of the custom status.