I am trying to upgrade my koha existing(16.05) to 19.11 version in a other system. I took db backup and restore properly, and run rebuild zebra command, everything done without error, but when I am trying to search in opac then nothing is showing & I got error in opac-error.log:-- [Wed Jun 17 18:32:10.017502 2020] [cgi:error] [pid 5081] [client xxx.xxx.xxx.xxx:56692] AH01215: [Wed Jun 17 18:32:10 2020] suggestion: oAuth error: Database unavailable (109) authorities Bib-1, referer: http://opacrri.local.net/cgi-bin/koha/opac-search.pl?q=science. In our existing system it's working fine. For my new setup I am using Debian-8.
This sounds like a support request rather than a bug. Questions about Koha should be asked on the Koha mailing list (http://koha-community.org/support/koha-mailing-lists/) or in the #koha IRC channel (http://koha-community.org/get-involved/irc/). Hopefully you've already seen the Koha documentation: http://koha-community.org/documentation/ You can also find options for paid support here: https://koha-community.org/support/