I have been having a problem for a while where Daily Player stats would not work. Only 'last month', 'last week', and full stats would work. It was an easy fix so I figured I should share it here for anyone else having the issue:
Go to install.dir/pages/players.php. On line 340 you should see this:
$minEvent = split("-", $dates[$rank_type-1]['eventTime']);
Change that line to this:
$minEvent = explode("-", $dates[$rank_type-1]['eventTime']);
Basically swap out 'split' for 'explode' as 'split' is no longer a function in PHP7. Save your file and that's it, daily player stats from the drop down menu should work as intended.