Problem with buddypress calendar??

I just wanted to make aware that when I installed the Buddypress corporate theme, buddypress calendar plugin then installed buddypress I got this error:

Fatal error: Class 'BP_Group_Extension' not found in /home/content/20/11461520/html/staff_intranet/wp-content/plugins/bp-group-calendar/groupcalendar/bp-group-calendar.php on line 103

did I do something wrong? How do you recover from this? or is it easiest to just reinstall and start over (for future reference)?

I deleted the file and started over. But still curious to previous question.

Thank you