I've written a class for a new TabPage type.
The only thing I've added is a couple variables which I can assign to the tab page in order for my app to identify which tab page is selected.

This works fine on my pc, and a few others, but I have one customer who is using my app.
When they run, and they open a new tab, the
TABcontrols.tabpages.add(NEWTAB) errors out.

I'm 100% sure that this is because it doesn't like the fact that newTAB is my custom TAB class.
When I did some debugging, his pc moved past the error when I just added a default tabpage type.

When I'm dealing with custom tab pages, is there anything needed to be coded on the tabcontrol to accept custom tabpages ?