In the folder that holds your project, and with the project not open in the editor, delete the following folders: intermediate, saved, and binaries. Everything in those folders is temporary and will be recreated by the editor when needed. You will then need to rebuild the project in Visual Studio and after that build completes should be able to open the project in the editor.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…