"Evaluated candidate is null - exception?" error causes the Build process to terminate

Building to periodically generate an error, "Evaluated candidate is null - exception?", which causes the entire Build process to terminate. Building can go on for a few seconds or for many minutes before this error is received. It seems quite random. 


It would be nice if the Log gave enough information to trouble shoot the error. 


But regardless, the Build process should not terminate on account of this singular error. 


Thank you.