Hi,
Ok, I have now looked at the file and it seems that all of these errors are related to the linked files. I also do not see
why you needed to link these files. Each one of these parts is just another assembly or sub-assembly of the same
model. I understand that if you downloaded a model of a pilot from somewhere you might link it but it isn't
necessary.
You are also building this model from the inside out and not from the outside in which is causing a huge amount of
unnecessary construction to take place that is over complicating the model. An example of what I mean.
You are modelling individual bulkheads and skins which to my count has meant the creation of 17 individual planes
just for the fuselage. Why? Are you trying to create an RC Model or a faithful reproduction of the aircraft as built from
the original designers plans? Most RC modellers would design the fuselage as a solid body and get the outside the
correct shape. They would then use surfaces and thicken to cut out the skin for the outside. The internal structure of
bulkheads and stringers would then be created using intersection cuts on the internal solid to create the actual
structure you would mount the skin onto. This is easily created using a simple sketch of a box the appropriate size
and a rectangular pattern. By building from the outside in I just have to get the outside shape accurate and then use
the tools to create the inside.

The errors you have in your model are all related to the linked parts. Have you tried to model changes to those parts
directly after you have linked them or are you opening the original part file and making changes then saving? If you
have linked the files and are direct editing them then there will be a conflict as fusion tries to calculate everything.
When fusion recalculates it will go back to the original linked file and not take into account any direct edit changes
you have made to it.
Cheers
Andrew