As far as I can tell this is never actually executed?
I was expecting that when a challenge is withdrawn, regardless of the circumstances, that the global script would fire once.
Could you describe in detail what your trying to achieve here and we might be able to better address this issue. Could you explain how you have tested this, so we can recreate the issue?
I have already accomplished what I needed to by moving the code into the WithdrawChallengeResponse cloud code script rather than the aforementioned global message script which was not being executed.
To reproduce it is quite easy though.
1. Create a cloud code script for Global Messages -> ChallengeWithdrawnMessage which
does the following: Spark.getLog().debug("global withdraw message")
2. Create a challenge.
3. Withdraw the challenge.
4. Note that "global withdraw message" was not logged.