please how to fix this error
2018-07-17 22:41:33.185 ===== TRACE ===== NEW CONNECTED USER 'a.bouamama'
2018-07-17 22:41:45.197 ** ERROR ** [V7.1.0] ERROR **
2018-07-17 22:41:45.197 ** ERROR ** [V7.1.0] on file 'C:Apache24htdocsphpmyadminphpMyAdmin-4.8.1-all-languagesprojeqtorV7.1.0projeqtormodelCron.php' at line (312)
2018-07-17 22:41:45.197 ** ERROR ** [V7.1.0] cause = A non-numeric value encountered
2018-07-17 23:19:15.000 ** ERROR ** [V7.1.0] ERROR **
2018-07-17 23:19:15.000 ** ERROR ** [V7.1.0] on file 'C:Apache24htdocsphpmyadminphpMyAdmin-4.8.1-all-languagesprojeqtorV7.1.0projeqtormodelCron.php' at line (207)
2018-07-17 23:19:15.000 ** ERROR ** [V7.1.0] cause = A non-numeric value encountered
2018-07-17 23:25:28.917 ** ERROR ** [V7.1.0] ERROR **
2018-07-17 23:25:28.917 ** ERROR ** [V7.1.0] on file 'C:Apache24htdocsphpmyadminphpMyAdmin-4.8.1-all-languagesprojeqtorV7.1.0projeqtormodelCron.php' at line (312)
2018-07-17 23:25:28.917 ** ERROR ** [V7.1.0] cause = A non-numeric value encountered
2018-07-17 23:25:59.961 ** ERROR ** [V7.1.0] ERROR **
2018-07-17 23:25:59.961 ** ERROR ** [V7.1.0] on file 'C:Apache24htdocsphpmyadminphpMyAdmin-4.8.1-all-languagesprojeqtorV7.1.0projeqtormodelCron.php' at line (207)
2018-07-17 23:25:59.961 ** ERROR ** [V7.1.0] cause = A non-numeric value encountered
2018-07-17 23:27:38.117 ** ERROR ** [V7.1.0] ERROR **
2018-07-17 23:27:38.117 ** ERROR ** [V7.1.0] on file 'C:Apache24htdocsphpmyadminphpMyAdmin-4.8.1-all-languagesprojeqtorV7.1.0projeqtormodelCron.php' at line (207)
2018-07-17 23:27:38.117 ** ERROR ** [V7.1.0] cause = A non-numeric value encountered
2018-07-17 23:31:21.868 ** ERROR ** [V7.1.0] ERROR **
2018-07-17 23:31:21.868 ** ERROR ** [V7.1.0] on file 'C:Apache24htdocsphpmyadminphpMyAdmin-4.8.1-all-languagesprojeqtorV7.1.0projeqtormodelCron.php' at line (207)
2018-07-17 23:31:21.868 ** ERROR ** [V7.1.0] cause = A non-numeric value encountered
1) Migrate to V7.1.3 (if not done yet)
2) Stop CRON (in administration screen)
3) Restart CRON