Free style and add-ons are a free XenForo Official Resource.
Premium style and add-ons are a paid XenForo Official Resource.
https://www.null-scripts.net/account/upgrades
Nulled version removed of license token system from official software is trying to check for PHP secret a token for the license after found a can be banned account customer license on official, also people can download a file then check license token to report on official software then may get banned.
To be a safe removal of license token after changed to nulled version.
If you are licensed of customer software, do not give to any people they may get you banned from official software possible. If you are licensed customer, you keep safe with your site only.