This is a new issue in version 2.1.1. This problem was not present in 2.1.0.
In bin/spark-class2.cmd, both the line that sets the RUNNER and the like that invokes the RUNNER have quotes. This opens and closes the quote immediately, producing something like
The quote above a opens the quote. The quote above b closes the quote. This creates a space at position c, which is invalid syntax.