I imported a model from GMod into Blender and a lot of parts of it look like this. Anyone know a fix?
Have you done any cleanup? Does the model have custom normal data?
All of those RED triangles are flipped normals…
Go to edit mode select all, and first do a Merge by distance ( almost always needed on an imported mesh like this, then I would use Triangles to Quads, as it helps the mesh smoothing and artifacts, with all selected use Alt +N and select Recalculate Outside and see if that catches all of them, if it doesn’t ( and since there aren’t that many ) select the individual faces and Alt + N > Flip Normals
No, and huh?
I’ll give this a shot
Please refer to the video.
In some cases, the object is not solved properly because it is not confirmed directly.
Currently, the problematic object has multiple objects combined, so it is necessary to check the status of the object and handle it appropriately.
If you haven’t checked the file, it’s just an estimate.
Common problems are solved, but sometimes not, it is not easy to find the cause.
Attaching even a part of the file will help solve the problem. 
※ The attached capacity is 5mb, and a large file should be attached to the outside and a link should be left.
I don’t understand
I would like to bring this topic to a close, as I have ultimately just given up on this model in particular and found another similar one. I will no longer be using this one.