Can't open dynamo,get this message

When I try to open Dynamo from Revit I get this message. How do I fix it?!Capture

Can you confirm what build of Revit, Dynamo for Revit, and Dynamo core you are using?

@Michael_Kirschner2 any ideas?

I am using Revit 2017 and both Dynamo 1.3.2 and 0.9 give the same error message. Dyanmo Core is 1.2 and 1.3


My only thought is a complete uninstall of all things Dynamo (core, studio, for Revit, all versions), ensuring the registry is clear, then a clean install of just 1.3 and 2.0.2. Others may have less nuclear options though.

How do you have both 1.2 and 1.3 core installed?

thanks everyone! I have uninstalled and re-installed and it works now!