The CommandBar Converter shows an error message when loading from an Access database.
1. The database must not contain a macro called "Autoexec".
2. The database must not be protected by "*.mdw".
3. The database must not be password protected.
4. The database must not have a start-up form.
5. In rare cases it may help to start the CommandBar Converter with administrative rights (Context Menu --> "Run as ..." --> "The following user" --> Administrator)
See also: RibbonCreator 2016 - FAQ Article.