Huge number of PHP errors every time backup runs

In my error log, I see loads of errors, most of which are the same but with different database tables mentioned. Here’s an example:

[15-Feb-2017 02:07:55 UTC] WordPress database error Duplicate entry 'wp_options' for key 'name' for query INSERT INTO 'wp_wptc_processed_dbtables' ('name', 'count') VALUES ('wp_options', 10) made by require('wp-blog-header.php'), require_once('wp-load.php'), require_once('wp-config.php'), require_once('wp-settings.php'), do_action('setup_theme'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, init_wptc_cron, perform_request_wptc, monitor_tcdropbox_backup, run_tc_backup, WPTC_BackupController->execute, WPTC_DatabaseBackup->execute, WPTC_DatabaseBackup->backup_database_table, WPTC_Processed_DBTables->update_table, WPTC_Processed_Base->upsert

There’s also many errors like this one:

[15-Feb-2017 02:07:55 UTC] WordPress database error You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-1' at line 1 for query SELECT * FROM wp_bp_xprofile_groups LIMIT 10 OFFSET -1 made by require('wp-blog-header.php'), require_once('wp-load.php'), require_once('wp-config.php'), require_once('wp-settings.php'), do_action('setup_theme'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, init_wptc_cron, perform_request_wptc, monitor_tcdropbox_backup, run_tc_backup, WPTC_BackupController->execute, WPTC_DatabaseBackup->execute, WPTC_DatabaseBackup->backup_database_table

As far as I can tell, the backup is completing, but I haven’t had a chance yet to check whether it is correct.

Thanks