YARN-891 augments the RMStateStore to store information on completed applications. In the process, it adds transitions from NEW to FINAL_SAVING. This leads to the RM trying to update entries in the state-store that do not exist. On ZKRMStateStore, this leads to the RM crashing.
ZKRMStateStore fails to handle updates to znodes that don't exist. For instance, this can happen when an app transitions from NEW to FINAL_SAVING. In these cases, the store should create the missing znode and handle the update.