If Koha is in strict SQL mode and you try to Synchronize -> Download records in the built in offline circulation interface the process will fail: CGI::Compile::ROOT::kohadevbox_koha_offline_circ_download_2epl::get_data(): DBI Exception: DBD::mysql::st execute failed: 'koha_kohadev.borrowers.cardnumber' isn't in GROUP BY at /kohadevbox/koha/offline_circ/download.pl line 84
*** Bug 30369 has been marked as a duplicate of this bug. ***
The in-built offline circulation tool has been removed recently with bug 33961.