From release notes for Zone Director version 9.9.1 - DATED - MAY 2015
https://ruckus-support.s3.amazonaws.com/private/documents/745/ZoneDirector%209.9.1%20Release%20Notes...=======
Officially Supported 9.9.1 Upgrade Paths
The following ZoneDirector builds can be directly upgraded to ZoneDirector build
9.9.1.0.31:
• 9.7.2.0.9 (9.7 MR 2)
• 9.8.0.0.373 (9.8 GA)
• 9.8.1.0.99/101 (9.8 MR 1)
• 9.8.2.0.15 (9.8 MR 2)
• 9.9.0.0.205 (9.9 GA)
• 9.9.0.0.212 (9.9 GA refresh 1)
• 9.9.0.0.216 (9.9 GA refresh 2)
If you are running an earlier version, you must first upgrade to one of the above
builds before upgrading to this release.
NOTE: The upgrade path from 9.9.1 to 9.10 is not recommended due to the fact
that the 9.10 release date occurred before 9.9.1 and therefore 9.9.1 includes bug
fixes that are not in the 9.10 code.
=======
Now release notes for Zone Director 9.10.2 - DATED JAN 2016
https://ruckus-support.s3.amazonaws.com/private/documents/938/ZD%209.10.2%20-%20Release%20Notes%20-%...========
Officially Supported 9.10.2 Upgrade Paths
The following ZoneDirector builds can be directly upgraded to ZoneDirector build 9.10.2.0.11:
• 9.9.0.0.205 (9.9 GA release)
• 9.9.0.0.212 (9.9 GA refresh)
• 9.9.0.0.216 (9.9 GA refresh 2)
• 9.9.1.0.31 (9.9 MR 1 release)
• 9.10.0.0.218 (9.10 GA release)
• 9.10.1.0.59 (9.10 MR 1 release)
========
there are other details that are important about factory reset you will need to think about
BUT this document from 7 months later makes no reference to the problems mentioned in May 2015. Is this Minority Report precog stuff?
Your call!
In case you are wondering I'm running 9.10.2 (R500+7363 mix) with no issues (for my configuration).