If you are having any troubles after upgrading to Backdrop v 1.19.0, please try upgrading Backup and Migrate module (if you have it installed). Some changes to Backdrop 1.19.0 seems to have uncovered a problem with Backup and Migrate that is causing some users problems. Watch for this error:
Call to undefined method DatabaseConnection_mysql::exec
The Backup and Migrate module has been fixed and a new release is available as of May 17, 2021.
For more information: