populate control from named range stored in addin

[MrBlackd]

I have attached a similar far simpler file that is reproducing the issue mentioned above.

In procedure UserForm_Initialize of Form UserForm1 I get
Error 380 (Could not set the RowSource property. Invalid property value. )

The problem is here:

ComboBox1.RowSource = ThisWorkbook.Names("myTypes")

Even if I could bypass it using On Error statements it will occur again in ComboBox1_Change when I populate ListBox1 in a similar manner.

I am guessing that I am not referring properly to the named ranges stored in the add-in.
Perhaps because it is an add-in.
However, if I change the IsAddin to False in ThisWorkbook Properties, then the ComboBox and the ListBox will populate with no error at all.

BTW you can also access the form using the ribbon button I created so as to be closer to the original file where the issue appeared.

Thanks again for your interest and help...