I've narrowed the problem down.

I can switch drawings now whilst my application is running.

I've created a combobox to switch drawings whilst my application is running and even ACTIVATE and REGEN the selected drawing:

ThisDrawing.Application.Documents.Item(ComboBox1.ListIndex).Activate
ThisDrawing.Application.Documents.Item(ComboBox1.ListIndex).Regen acAllViewports

The GETPOINT line is only successful in the drawing that was active before I started my application:

PrikPnt = ThisDrawing.Utility.GetPoint(Basepnt, PrikPointTexT)

The error I get in all other drawings I select and activate:

error.jpg

Anyone any idea what's need to be set before I can use it?

Thanks