Revit MEP 2009 - Licensing Activation error

[Anonymous]

I screwed up and installed Revit MEP 2010 on a new computer thinking we wouldn't use Revit MEP 2009 anymore but found out that the designer still wanted 2009 until he got used to 2010. So anyway 2010 license activation went fine but the 2009 gives an "ADEreg" error and crashes. I have fully patched 2009 to best of my knowledge but can't figure it out.

What could be causing this?

Is it because 2010 was activated first?

KHeinz

[Jrobker]

Your not going to get an answer here. I have seen a few post similar to this with no responses.
Installing multiple vertical softwares in the same location can create problems with paths. Installing a more current version before a previous shouldn't be an issue. You can try and reverse the installs.
Does this error happen when you try to register/activate?
If this is a .dll file it could be a corrupt dynamic link library.
Your best bet is to call Autodesk customer support

[Anonymous]

Thanks for the reply. I will contact support directly.

Thanks again,
KHeinz