How are you updating PERC FW? Are you using iDRAC or Lifecycle Controller? If you are using iDRAC or Lifecycle controller then you need to use .EXE file (Update Package for MS Windows) to perform update. You can download the same from below link [URL] 
We have two tower servers each of them has 8x2Tb HDD configured into RAID5. Recently due to temperature increase, 4 of them showed failure. Hence raid degraded, we had backup so no worry for that. But I was looking on disk one by one as PERC710 raid controller doesn't support any HDD without raid, therefore to check these drives I cleared the foreign configuration, and started to build Raid0 for each disk just to check which of them were working. But strange thing is that Out of 16 drive each one of them shows 'Ready' status as I plug them. But as soon as I configure them to build raid0 each of one them converts into 'failed'. So we are thinking that these disk are actually failed. But as I was googling these much disk failure, I got one of thread here, which said it is not really possible to failed even 2disk together, there might be some firmware or BIOS related issue. Hence I updated iDRAC and BIOS of the system. It's working fine but I also wanted to update SAS RAID firmware, but as soon as I start the upgrade I get this message 'This update package is not compatible with your system configuration'. I tried following files: SAS-RAID_Firmware_1C4T9_LN_21.3.1-0004_A06.BINSAS-RAID_Firmware_9MHJ5_LN_21.3.5-0002_A09.BINSAS-RAID_Firmware_K4HJ0_LN_21.3.2-0005_A07.BINSAS-RAID_Firmware_KKR9J_LN_21.3.5-0002_A09.BINSAS-RAID_Firmware_XTVPT_LN_21.3.4-0001_A08.BIN   I am also attaching screenshot of current version of BIOS and firmware. System has Ubuntu 20.04 LTS installed.[IMAGE]
Poweredge T620 sas raid firmware update