8865 - MPP Firmware downgrade from 11-5-3 to 11-3-3

[ian.ryder]

I have a Cisco 8865-K9= V03 which has been converted to MPP and is running 11-3-5, but I want to downgrade to  11-3-3MPP.  I’ve followed the instructions here  https://upgrade.cisco.com/MPP_upgrade but get "Unable to upgrade because of SW or HW incompatibility"

Full error below:

“{02/05/2022 14:04:18][https://cloudupgrader.webex.com:443/mpp_firmware/8845_65/cmterm-8845_65.11-3-3MPP0001-377_REL/sip8845_65.11-3-3MPP0001-377.loads]Upgrade Failed. Reason: Unable to upgrade because of SW or HW incompatibility”

The conversion guide mentions "All versions of 8800 series audio phones listed above can convert to MPP firmware but V15 and later hardware versions will require minimum 11.3.3 MPP firmware once converted and can not downgrade to earlier MPP firmware versions."  Does this mean they cannot be downgraded to any firmware lower than they are currently running, or can be downgrade to 11.3.3 and just not prior to that.

Any help appreciated.  Thanks

[Geovani]

Hi, 

Your tittle here is a bit confusing. You say downgrade 8.3.5 to 8.3.3? 

Anyway, with V03, you should be able to downgrade to a lower firmware. Can you please try downgrading it locally? 

[ian.ryder]

Hi, thanks for the reply.  And yes not sure what I did with the title.  I have corrected.

I've also tried a downgrade locally and this fails.

[Geovani]

Can you please outline the steps you used for the conversion? Did you use control hub? or the steps on upgrade.cisco.com?