I'm not sure how you are going about this so its harder to troubleshoot for you.
Two things to check.
In your void family, be sure that when you select the "extrustion" that makes your void, in the properties you set it to "void" and not "solid".
That is step 1.
Step 2. you must cut the element (slab in this case) with the void, otherwise you just get an orange "void" extrusion that doesn't actually cut anything. Select the element to cut (slab), "cut geometry" and select the element you want to cut it with (void).

Hi Karalon, thank you very much for your fast response! Let me try to explain it from the beginning: I have some customized ball shaped elements like the following:

[0.jpg]


The first step was to model them in a Revit family (general) as a compact element.
I have the problem that I can not place them in a revit family (Slab), so that the slab got reduced by this void elements. Even if I try to cut the elements, it is not allowed to pick that void elements:
[1.jpg]

Therefore it doesn't matter which kind of elements it is. Its for all of them, if they are imported from another Family. Its only working for in the family created objects. I've checked that it is allowed to use them as void elements in other families, but its still not working.

Do you see my problem? Do you have any other suggestions how to model?

Thank you very much in advance! I would be more than glad for help

best regards

Can you share your revit family so I can test it, and see what you have set?

Also, try making the ball void thing as a "profile" family instead.
Then do an "insitu-component" and import the profile family of the ball void thingy.

Complete the steps, make sure you set it as a "void" (and not a solid) before you finish the family off.
Now you should have it working there so you can cut your slab geometry with the void.