When opening AECOsim a Class Factory VBA error occurs and has to be accepted multiple times to get out of it.
Cannot open AECOsim without getting an error message.
Please note that resolving VBA problems may require the intervention of your IT support teams or services as these are primarily Windows system matters. Some level of administrative permission is needed for most of the potential solutions.
http://communities.bentley.com/products/building/building_analysis___design/w/building_analysis_and_design__wiki/10509.aspx
If you have followed the solution to this problem in the Technote in the above link and you still get the error message, please also try the following: