This weird! Had this error this morning and somehow it mystically cleared, now its back!
Any ideas how to clear, it look OK to me.
Have You tried to play with accuracy setting?
There is in Your model 0.0001, I tried to set to 0.001 but it allows only values from 0.005 to 0.5. I set 0.005 and regeneration fails on Trim 6 feature.
Now I cannot return accuracy back to 0.0001.
That's just the way it was sketched against the reference. When I select Tools-> Geometry Checks there are no errors. Can't see how that can affect the merge or can it?
I don't know but if look at the model there are some holes os small surfaces and may be the F46 and F27 don't connect or intersect.... I think the bottom of the blade should be coincident with the plate