Problem :
I'm trying to open an xib with Xcode through Visual Studio and give me this error. It started to appear since I did update in Visual Studio for Mac and in Xcode.
Visual Studio for Mac Version 8.0.1 (build 1)
Xcode Version 10.2
This is the file I try to open in Xcode. This is the error that appears
I discovered this solution and it worked for me. I hope it works out for you.
Xcode can not find the solution to the problem because VS for Mac creates the project on another page, so I deleted the page that is generated by VS for Mac called Xcode and when starting up again it will already create a folder with the solution and run through Xcode.