What does this mean? I haven’t been on in a few months.
That’s generally mod related. A mod tried to spawn/create something you’re not allowed to. Could be as simple as a mod that creates extra smoke particles or as nasty as a pocket nuke hack.
It typically happens after a mod author comes up with a great new way to do something by creating new objects for effects, which isn’t allowed on altis for performance reasons (and others).
Two approaches here assuming you didn’t just recently add a new mod and already know the problem:
plan a> Look for recently updated mods and either read the comments for other people with similar issues or just disable it and see if you can get in without being kicked.
plan b> Remove all your mods and put them back a few at a time until you get kicked at which point you’ve found the culprit.
plan c> Remove half of your mods and test. If you pass, add back half the ones you removed. If you fail, remove half again. Repeat until you find the mod causing the problem.
I prefer C because it makes some people’s brain melt.
For any future references: as my friend Sny here said, script 15 can essentially be considered “mod not allowed” although it also filters scripts i believe.