https://community.appian.com/discussions/f/administration/24003/appian-upgrade-issues-on-21-4-600-0---violation-of-unique-key-constraint-primary-data-sourceWhile upgrading from 20.3.1370.0 to 21.4.600.0, received below error. i.e. Numerous errors for each user data, 2022-03-15 12:21:31,341 [localhost-startStop-1] ERROR org.hibernate.util.JDBCExceptionReporter - Violation of UNIQUE KEY constraint &#39;usr_username_ucen-USTelligent Community 12https://community.appian.com/thread/92437?ContentTypeID=1Fri, 18 Mar 2022 13:03:08 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:b0af1aca-91a9-4e7c-a2b1-0e19e7d5bdc8Karikalan Ramakrishnan<p>Great, thanks Steve.</p><div style="clear:both;"></div>https://community.appian.com/thread/92436?ContentTypeID=1Fri, 18 Mar 2022 12:58:20 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:f5b1e40a-0dad-4342-8a29-5d02ecbc2e3dStefan Helzle<p>I think most people here are not sys admins, but Appian designers.</p> <p>Try to send an email to support@appian.com.</p><div style="clear:both;"></div>https://community.appian.com/thread/92434?ContentTypeID=1Fri, 18 Mar 2022 12:55:05 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:3d30bc15-908c-41d4-a4c6-27d633bcb049Karikalan Ramakrishnan<p>Thanks Steve, sorry. I don&#39;t have access to Appian support portal for now. That&#39;s the main reason, trying to get some help/clarifications here if this is known issue and anyone handled this type of error while upgrading Appian. thanks again.</p><div style="clear:both;"></div>https://community.appian.com/thread/92433?ContentTypeID=1Fri, 18 Mar 2022 12:51:11 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:60e13e0a-6314-455e-8c40-2cda760658e9Stefan Helzle<p>I recommend to contact Appian support.</p><div style="clear:both;"></div>