Hidden Boots Unlocker for the latest update [Feb,2018], will not work for previous updates. If thats the case, just download the unlocker for the specific update of your FIFA 18.
1) Will work with any mod.
2) If you want to make it work with "BOOTACK NICKED V2.1", as always:
Remove all your applied mod> Apply Bootpack>Apply this unlocker.
Will work. Trust me, tried and tested.
PS: THIS IS ONLY TEMP FIX. I will be back with more. Stay Tuned.
***THE NEW UPDATE V2.2 IS OUT, GO CHECK IT OUT HERE***
Thnx for patience and love.