Combine tool error: "ensure there's a clear overlap" but there IS a clear overlap

[FrodoLoggins]

I need to machine a mold but it has a feature that I'm not able to get to with a 3 axis machine.

I'm trying to cut "Bottom" with "Molded Part" under the "Machined" component:

But I can't due to an error:

But there IS overlap:

Model is not mine, imported from STEP file.

If I also try and combine Molded Part in Machined component with Part in OG component (the two green components) I get the same error. Even though Molded Part is just a copy of Part but with sliced geometry.

I reallllllly need a solution to this ASAP if possible.

[jean.flower]

Nice filename! 

I took a look at this.  You're right that there is a good intersection between the two inputs for the combine, in some places, but also I can see one region where the geometry of the Molded Part is nearly, but not exactly, the same as the geometry of the Bottom part.  I changed the appearance of those faces in red in this screenshot.  If there was a timeline we might be able to roll back and see some nice way to align the geometry (e.g. by adding constraints to a sketch).

I built a new body (shown in green) and subtracted it from the Molded Part (in Combine 1). Then the reduced Molded Part can be subtracted from the Bottom (in Combine9).  The overlap you wanted to trim away has, for the most part, been cleaned up.

I'll attach a new f3d, ldhflshflskhflsf_7.f3d, in case it's any use for you.  Hope it helps somewhat.

Jean