I've a program written in VB6 which starts Autocad:
Public oAcadApp As AcadApplication
Set oAcadApp = CreateObject("AutoCAD.Application.18.1")
on a PC with XP 32 bit there is no problem but on a PC with XP 64 bit -> oAcadApp stays Nothing, while Autocad does start up properly.
Do I miss something? Is there a difference between 32 bit and 64 bit for VB6?
I've got a similar problem...
I'm using 'AutoCAD_Instance = CreateObject("AutoCAD.Application")' to open AutoCAD... I'm not including the version because my company upgrades every year and I don't want to have to re-issue the app each time...
On WinXP, one user has both 2011 and 2010 installed... it works perfectly, opening the last version opened (same as double-clicking on a dwg file in Windows)... but in Vista, I get the error you mentioned...
We only use XP - 32 bit and Win7 - 64 bit so with Vista I can't help you.
On Win7 - 64 bit it works with Object, but it's a workaround at the problem and isn't a nice solution.
But it works for me.