Downgrading a Firepower 2110 to ftd 6.4x

[JohnW2]

I need to downgrade a new 2110 with an ASA image to ftd 6.4.x. I've done this with no problems to 7.3, but here's the problem. The 7.x image is a .SPA and 6.4 is a .tar. 

When I follow the procedure I previously used here, I get the following failure:

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ciscoasa(config)# boot system disk0:/Cisco_FTD_SSP_FP2K_Patch-6.4.0.17-26.sh.R$
INFO: Converting disk0:Cisco_FTD_SSP_FP2K_Patch-6.4.0.17-26.sh.REL.tar to disk0:/Cisco_FTD_SSP_FP2K_Patch-6.4.0.17-26.sh.REL.tar

The system is currently installed with security software package 9.16.2.3, which has:
- The platform version: 2.10.1.172
- The CSP (asa) version: 9.16.2.3
Preparing new image for install...
!Image download failure -
Error status: Download failure - Unable to open downloaded image
Error message: Unable to open downloaded image#
ERROR: Unable to set this url
ciscoasa(config)# boot system disk0:Cisco_FTD_SSP_FP2K_Patch-6.4.0.17-26.sh.RE$
INFO: Converting disk0:/Cisco_FTD_SSP_FP2K_Patch-6.4.0.17-26.sh.REL.tar to disk0:/Cisco_FTD_SSP_FP2K_Patch-6.4.0.17-26.sh.REL.tar

The system is currently installed with security software package 9.16.2.3, which has:
- The platform version: 2.10.1.172
- The CSP (asa) version: 9.16.2.3
Preparing new image for install...
!Image download failure -
Error status: Download failure - Unable to open downloaded image
Error message: Unable to open downloaded image#
ERROR: Unable to set this url

---------------------------------------------------------

Any ideas on how to get back to this version? 

[Rob Ingram · Accepted solution]

@JohnW2 download the installation package - "cisco-ftd-fp2k.6.4.0-102.SPA" image, once installed then you can patch to 6.4.0.17

https://software.cisco.com/download/home/286312107/type/286306337/release/6.4.0

Why do you want to downgrade to such an old version that is almost EOL, 7.2.5 is the recommended version. Also if you are using FMC then depending on the FMC version you may not be able to manage FTD 6.4.

[JohnW2]

The install file worked. Thanks!

We're stuck on 6.4 because of an outside group. I'm with you on the recommended release. Hopefully they get that approved soon!

[Marius Gunnerud]

.tar is an upgrade file.  You need to use the install file which would be the .SPA