Only one MDI Form allowed (Error 426)

A project can only have one MDIForm. This error has the following causes and solutions:

• You tried to load a file containing an MDIForm into a project that already has an MDIForm in it.

  Remove the file containing the loaded MDIForm before loading another.

• You tried to load a second instance of an MDIForm created with a Dim or Set statement.

  You can only create one instance of an MDIForm in a project.