If a form is not one of the default forms you can delete it. Here are the three ways to delete a form:

1. Select the form within the Explorer dialog and right click the mouse for Windows//Control click for Mac to open the contextual menu. Choose the Delete Form item within the menu. The form should now be in the trash. If the form is one of the default forms, this item is dimmed and cannot be deleted.

2. Click on the form in the Explorer dialog which you want to delete and press the minus button located at the bottom of the form.


If the form is one of the default forms, this button is gray.

3. Select the form and drag it to the trash.

Other Resources:

When can a form not be deleted?
https://kb.4d.com/assetid=47234