MVBA's that worked in previous versions SS2 are not working in the new version SS3 or again in the old version after working in the past.
If you have multiple installs of GEOPAK (ie SS2 and SS3), you may need to register the geopakcom.
try logging on as the administrator and running the application geopakcom.exe which is located in the bin folder of Geopak; this will ensure that dll for the MVBA is registered.
A more complex case:
The problem was with the VBA Core. We ran a “repair” on the ”Visual Basic for Applications(R) Core “ in the one of the SCCM Management tools and that cleared the problem
See also: https://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki/12619.run-time-error-vba-programs-that-reference-the-geopak-8-11-object-library-no-longer-work.aspx