/scoreboard objectives add yellowWinBackslash dummy
fails at runtime "Objective name can only be 16 characters"
This would be an easy error to catch at parse/load time.
I spent time debugging my functions trying to figure out why the exact same code worked for my red team and blue team but not my yellow team, until I realized it was because my yellow team's objective was ignored because its name was too long.
this is not fixed (unchanged) in 18w01a, please re-open