Every now and then I come across a Visual Studio solution file that won’t open, because the Visual Studio Version Selector can’t figure out what to do with the file — even if the version specification in the header of the file is present. This usually happens with solutions that look like they were machine-generated. In fact, I had it happen to all the solutions SlimBuild produced when I first started building support for that operation.

So far, the problem I’ve seen with all the broken files is the lack of a UTF8 byte order mark at the beginning of the file. You can fix the problem by opening and saving the file with an appropriately powerful text editor, or by manually opening the file from the correct version of Visual Studio, causing a change to the solution (such as renaming a configuration), and hitting “Save All.”