To re-enable VBA in the registry:
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\ESRI\ArcMap\Settings, double-click the PreloadVBA variable and set the value data to 0 from 1.
If the PreloadVBA has a value of 0; VBA is not loaded (disabled) when ArcMap starts. If the PreloadVBA has a value of 1; VBA is loaded (enabled) when ArcMap starts.