Hi Amir,
If upgrading to the 100.10.0.500 does not work, then you might have to upgrade the AP to the 9.x with the below upgrade path in order to upgrade to the 100.x version.
8.2 >> 9.1.2.0.8 >> 9.3.1.0.20 >> >> 9.5.1.0.50 >> 9.6.1.0.15 >> 9.7.0.220 >> 9.8.2.0.15 >> 9.9.1.0.52 >>
Below are the software files:
https://support.ruckuswireless.com/software?filter=21#firmwares