The upgrade process adds several database tables; not sure if installing an older version of WCS would strip them out. There is the possibility of the downgrade corrupting the db. You may want to open a TAC case and inquire about it.
The 2 feasible options would be to either do a fresh install of the desired version and restore a pre 5.x db backup, or just start all over with a fresh 4.x.x.x. install
You could also try building a test machine with 5.x, make a backup from the production wcs server and restoring it to the test machine and see what happens when you try to downgrade to 4.x.x
Just to satisfy my curiosity, I upgraded my WCS to version 5, took a backup and downgraded back to version 4 just to check if it would work - but no, it refused to restore from a newer version. I saved a copy of the v4 database which restored fine.
Transferring Crash file from standby: Login to the Active WLC in HA.
From CLI: (Cisco Controller) >transfer upload datatype crash (Cisco
Controller) >transfer upload filename (Cisco
Controller) >transfer upload mode tftp (Cisco Controller) >transfer
This is the start of a display filter cross reference between Wireshark
and OmniPeek. The 1st installment is a table of advanced filters. More
filters will be added as time allows. It is a living doc, so check back
for changes every so often Please feel f...
I have created a Powershell script to automatically add a Wireless Guest
User on Cisco WLCs. (tested on 2500 Series) The script should be
completely self explanatory. Prerequisites: Powershell SNMP Module
(Install-Module -Name SNMP) SNMP Write Access to y...