When I try to place an Assembly Feature on a specific part (e.g. Hole, Cutout, etc.) the Assembly Feature does work. Why?
This problem occurs if the Design Body in the part file is not marked as an Assembly Body, which means it cannot be modified by an Assembly Feature. To allow this type of modification, you need to right mouse button click on the body and select 'Activate assembly body' from the context menu. The body will then be indicated as the active Assembly Body by the orange blocks icon.
Here you can see that the Design Body is not marked as an Assembly Body. This problem could happen if, for example, you added a new body, then activated it as Design Body and subsequently removed it.
OS Version: 764SP1