mcperformance on "[Plugin: Backup Scheduler] Plugin could not be activated because it triggered a fatal error."

Tried to activate plugin and received this error message:

Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM in /home/content/74/7994074/html/wp-content/plugins/backup-scheduler/core/feedback.class.php on line 141

https://wordpress.org/plugins/backup-scheduler/