I am running the C11.0.13630 build.
But pointing at an earlier C11 environment. (11.0.13401)
Compiling a hand-coded project I got
“An Unexpected Error occurred while building this project”
Completely by fluke, I tried turning off the two new Project settings,
Dynamic Base, and Data Execution Prevention.
Error went away.
To change project settings, go to Project menu, Project Options, Compiling tab.