Callback Crashing

I have a callback from a Framework that crashes when it is called. I suspect this has to do with the thread that it’s calling into causing some issues.
I’m sure this has been covered a lot, but I’m not finding a good reference.
Can someone point me to best practices and where limitations may be?

If you don’t show code, we can’t help.

Callbacks on threads not created by Xojo is not supported.

So either use a plugin, if one exists.
Or ask framework vendor to dispatch callbacks on main thread.

Thank’s Christian. This is what I needed to know.