A bit of a strange one this.
I've built a part from sheetmetal which has various cutouts and holes.
One of these cutouts is for a binding post which has a notch I want to locate at a 45 degree angle.
I've added Centrelines which have been set at 45 degrees off horizontal / vertical.
I've then used those centrelines as a reference for adding the notch:
This appears to be fine.
I save the sketch then once back to the part, I extrude the sketch to generate the holes. That works fine.
I then pattern the extrusion 9 times. Again all appears OK.
I can regenerate the part, everything is fine. I save that part as "base-rear".
However now that I've used that part in an assembly "9ch-short", the assembly fails at regeneration with the following message:
9CH-SHORT regeneration completed with atypical feature or component status. Failed: 1. Child of Failed: 8.
BASE-REAR feature (ID = 9865) referenced by pattern is missing.
The Regeneration manager gives me this:
This appears to be linked to the diagonal centrelines. If I go back into the part and delete the smaller binding post cutouts with notches, the assembly is fine again.
What am I doing wrong?
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Found the cause 
It's actually with some other circle holes in the corners of the big one (for an Neutrik XLR D-shell cutout). Nothing to do with the diagonal lines / binding post holes I mentioned earlier.
There are no issues whilst those holes are there.
But as soon as I remove them, that's where the problem starts.
It's strange because those holes don't reference anything else, and every other dimension is defined and not weak.
The problem is still there if I remove the pattern for the 9 sets of cutouts.
If I delete the entire sketch (and extrusion), the problem remains ?!?
There are no other parts in the assembly that use those holes as reference, so I really can't see why there's a problem.
It might just be easier to start a new assembly, but it's a bit of a pain as there's quite a lot to it and will take a good few hours.
edit: maybe it's my assembly file that has become corrupt somehow. Is there a way I can do a healthcheck on it and clean out any old / irrelevant data that might be the cause of the issue?
