Especially if you are working with design backgrounds or swim lanes (see Pools and Lanes) and want to drop M-Files objects from the left side menu onto them, it may be useful to disable the 'MFAcceptDrop' option.
Normally, when dragging and dropping M-Files objects, the contents are replaced from existing elements so that you can easily replace the linked objects. But if you don't want this to happen, for example:
then disable the 'MFAcceptDrop' option by unchecking it in the Properties menu. The shape will now no longer accept a drop of M-Files objects.