"It is not possible to do this operation if a Max object is being created..." error

Problem​

When creating your own libraries you get the error "It is not possible to do this operation if a Max object is being created. Please, open the library browser from the Max modify panel and try again".

Solution​

Please open the library and create your items from the Modify tab.

This happens when you open the library browser from the Select button found in the Create Panel. There are certain restrictions in Max on create or editing a library when while Forest object is also being created. For this reason, if you want to edit a library you should always use the Library button found in the Geometry rollout that's available only when you're in the Modify Panel.