Thanks for taking the time to open a feature request!

Is your feature request related to a problem? Please describe.
this is just an error in my authentication plugins such as AdvancedLogin and Authme every time it finishes authentication sometimes items from ITEMJOIN crash the server

Describe the solution you'd like
may support the plugin if the player has authenticated, itemjoin is immediately obtained

Describe alternatives you've considered
I don't think so

Additional context
Nope

So I may need more context.
AuthMe is already supported; https://github.com/RockinChaos/ItemJoin/wiki/API-&-Dependencies#how-does-authme-work

As for AdvancedLogin, they do not appear to have an available API and it's a premium resource so I can't view their code to see if they do in fact have an API or not. Since AdvancedLogin does not document any API support I am unable to add support for it. However, AuthMe is already supported.

EDIT: Marking as inactive, please reopen this issue if you need additional support.