Updating to Filr 3.4 may fail with the following error:
One of the reason for failure could be MySQL or Filr Search is down. You can refer to the logs at /filrinstall/post_update.log for more information.
Resolve the issues with MySQL or Filr Search, then do the following:
Log in to the Filr Appliance Configuration Console (https://appliance_ip_or_dns:9443) as vaadmin.
Click Online Update.
In the Needed Patches, even though no patches are available, click Update Now.
This is an important step and will ensure to update the patch successfully.