Building from my SLN file getting build errors

Hey guys!
I’m working on a project with some friends. We’ve got our source control set up with p4v. Now it’s a blueprint project, and I’d like to do some C++ in it. However I cant build From the SLN file.

I’m getting a build error each time, and it looks like it’s because the files that are needed for the build arent writable?

Is there a way around this? LIke, is there a way to make to make the files needed writable? all the time? ALSO is there way to make this the case, for my teammates as well? They’re just opening the project file, and that’s working so far, because they’re artists. But I’d like us all to build from source if possible. LMK what y’all got in mind! I can post the wall of text too if that helps.