Can't Stay Logged In
 

I'm running vb 3.7.3 and today I got this issue:

When I log in it'll say logged in succesfully then refresh the window, but then I'm logged out again!

This happens all the time. I've used tools.php to reset all sorts of stuff such as cookies, but to no avail.

However I can stay logged in via admincp.


Please tell me how to fix this issue. It's very annoying. BTW I"m not so tech savvy so need a detailed explanation.