We do a whole mix of development projects, from Winforms to web projects to flat HTML sites. And we're switching between them all the time.
It means that our IDE of choice is Visual Studio even for looking at flat HTML sites. So it means we might sometimes open an HTML file or even a CSS or .less file for a brief look at an issue even while we have a Winforms solution open.
Obviously that must be what we've done because now we see in the Error List 3 errors from a stray/random .less file that has nothing to do with the current project.
It doesn't stop the project building and running, of course. But it is slightly distracting to see the errors persisting there, and it's definitely a pain to do an F8 cycle through the current project's errors and encounter these "foreign" errors repeatedly.
Restarting VS doesn't get rid of the problem.
Edit:
For a given project I've tracked the .less file down to the .suo
file. I guess I could delete the .suo file but I'd lose a bunch of settings for this project. It'd be nice to know how to remove the .less file from the solution. What are <MiscFiles>
any way?