I don't foresee any issues with this. Prior to upgrade to 11.20 SR16, did the customer perform backups? The below is a snippet from a Qlik Support article on reversion from major release version to the previous major release version. As you are performing a reversion from one SR to the previous SR, it may be overkill.
Before ANY upgrades, take a backup of the C:\ProgramData\QlikTech\ folder, and any other data generated folders that you might have defined (e.g. log locations, QDS Application Data Folder, Source Documents). If you have already made an upgrade and do not have any copies of C:\ProgramData\QlikTech\ folder, older copies of the QVPR only exists at C:\ProgramData\QlikTech\ManagementService\QVPR\Backups, which can be used to restore QDS (but no metadata), QMS and service intraconnectivity settings. Remember to use a zip file from when you are sure the QMS was running on an older version. At point 3 below, the content of the relevant zip needs to be extracted to C:\ProgramData\QlikTech\ManagementService\QVPR\ .
QVS, QVWS and DSC service-specific settings are contained within the individual folders within C:\ProgramData\QlikTech\ and NOT within the QMS repository folder. The QDS reload metadata exists in the QDS Application Data Folder, namely by default C:\ProgramData\QlikTech\DistributionService , which will be automatically regenerated if deleted during rollback (except logfiles).
If you are forced to revert, do the following:
1. Uninstall newer version
2. Remove the newer copies of files in the "QlikTech" folder and other data generated folders from your newer installation.
3. Recreate the "QlikTech" folder containing older copies (backups) and other data generated folders from your older copy. The repository, user documents and other files have been updated to newer versions when you upgraded and is not always backwards-compatible.
4. Install the older version.
5. Start the services.
Hope this helps,
I have raised this with Qlik Support too. Not sure at this stage if the did actually perform any sort of backup as we were no involved in the upgrade.
I know in the past I have downgraded successfully , my system, but that's just a PC based test system where is really doesn't matter if anything goes wrong.
I did also make the point when logging the support case that the release notes for 11.29 SR 16 make no mentioned of changes to the quarantine period for doc cals:
QlikView 11.20 SR16 – Release notes 1
QlikView 11.20 SR16 contains the following updates:
Changed quarantine of Named user CAL to 7 days
The quarantine period of a named user has been changed from 24 hours to 7 days
My support tech @ Qlik apologised for this and stated he would investigate with R&D.
Will keep you posted on the eventual outcome..