Yesterday I have Uploaded files of Aoe scheduler (which I had downloaded from GitHub) through FTP on my project.
But when I setup schedules from admin, it wasn't working. I got error in report files as "last_seen" column (and some other column names) are missing in the table cron_schedule (I checked into DB and yes they were not there).
So, to fix this I have dropped the table through php myadmin, downloaded Aoe scheduler V 1.5.0 from here and uploaded these fresh files to replace the previous ones.
But, now the issue is that the cron_shedule table is not at all being created in database. so the schedular options are not working in backend.
I need to reinstall this module to make emails work.