WLC 5520 or 8540 upgrade failing with: 'Failure while validating the signature!'

[Jeffrey Keown]

Some 5520 and 8540 controllers shipped from the factory without manufacturing installed certificates activated.

The first symptom typically observed is the inability to access the controller via https. (Temporary workaround: enable http access.  CLI: config network webmode enable)

Code upgrades will also fail due to an unactivated certificate:

FTP Code transfer starting.

FTP receive complete... extracting components.

Failure while validating the signature!

This issue is documented in the following bug:

 CSCuv97685    5520 or 8540 may have no Manufacturing Installed Certificates

This condition can be recovered without replacing the unit.

Refer to the following document for the recovery procedure, or contact the Cisco Tac for  assistance:

https://supportforums.cisco.com/blog/13046816/recovery-missing-85405520-manufacturing-installed-certificates

[Scott Fella]

Great info. Anyway you can post the solution?  We actually ran into this today. 

-Scott

[George Stefanick]

Thanks for sharing .. So what is the fix and what date range of equipment is impacted ? 

[Jeffrey Keown]

Hi Scott,

Done.  added another blog post with the recovery procedure.  Original post edited with link.

[Jeffrey Keown]

Hi George,  take a look at the release note for this bug:

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuy67885/?reffering_site=dumpcr

[Scott Fella]

Thanks Jeffrey!

[sotoncisco]

This is just tremendous

"More Info:This problem is supposed to have been addressed by manufacturing for all units built after 9 September, 2015.
Unfortunately, the manufacturing process change did not fix the problem."