Build Failed. See the build log for detail

Lots of times dealing with this error. I just closed and reopened. It happens every time I add a solution and then delete it. I think Xamarin Ide is not a really good Ide, not in Mac at least.

I got the same error when trying to build. Without having noticed I had been logged out of my account, which caused the error. Curious that I wasn't prompted to relog or given information that I wasn't logged in.

In my case, i did`t Indy (or higher) License. When i started trial period, the problem was solved.