Just had it happen again
This time around I saved the offending part.
Enclosed you can find the original parts and the original ASM as well as the BAD part with the surface that gets corrupted without doing any editing on the surface nor the part of the surface nor the ASM that has the different parts in it. Not even editing the higher level ASM that is a combination of this ASM and some other parts.
The only thing I was doing was editing the location of some completely different parts in the ASM above it all.
In other words while editing the location of a non related part what so ever in ASM1 - that also has among other things ASM2 in it, which in turn has ASM3 in it, which contains a part with a feature that is a surface, that said surface suddenly has an error.
I will try to do some test...
But alway I import it with a 3Dconnect, break the references fix the file as solid and save as SW file....
1-One only thing to fix it's OK
2-Serius problems to fix....try to download it again
I fix it.....holly cow tooooooooooo serius problems but I fix it
Thank you for looking and trying to find a solution for when it goes wrong.
There's indeed several ways around it and one being making it so that there's no surface features at all.
By the way, I downloaded it from Trace Parts directly, cutting out the middle man that is 3Dcontentcentral.
The point is that a surface feature getting corrupted without anything changing an iota of the feature amounts to it getting screwed up in the recalculating of the feature when it gets rebuild.
This happening to any feature should NEVER happen, not even if it's an imported feature. This means that there is a nasty little bug buried deep into the code that only sometimes pokes out it's head.
I see...sometimes *.XT to solidworks will be the best solution.
If you open the part 161586002_02.SLDPRT and use Import Diagnostics on the surface feature, you will see that the errors are already there. The issue here is that the warning is not shown in the tree, not that the errors aren't in fact in the surfaces already. If I do a ctrl-Q in SOLIDWORKS 2018, then the warning shows. My guess is that while you were working, a deep enough rebuild was triggered to update the surface and that made the warning appear. Again, the problems were always there, just not shown in the tree.
This file is from an older version of SOLIDWORKS and it likely was saved in the state without a warning in that version. That could possibly happen if whoever saved it had warnings in the tree turned off in the tree in Tools, Options but there may be other reasons for it as well (it could be a bug or it could be something to do with how Trace Parts made the part). SOLIDWORKS won't rebuild or force rebuild parts on open,since you could imagine the performance implications of that, so the hidden warning stayed hidden until the rebuild of the feature was triggered.
So, could this be improved so these types of hidden warnings always display when opening if the option to show warnings is turned on? Perhaps, but there may be performance implications to doing so since all features would then have to be looked at and possibly rebuilt to ensure all warnings are shown.
Cheers Jim for clearing that up.
It was driving me bonkers.
In future I'll refrain from using parts downloaded in SW format and just use extra time needed to convert Parasolids or similiar.