I have found if I log out of Instagram on all browsers and then log back in on a different browser, it will allow me to enter again. Example: I am on Firefox Instagram when it give me that "you can not enter" message. I log out of Instagram on Firefox, chrome, and explorer. Then I log back in on Chrome and it will let me enter again. Also, the first thing I do in the morning is look at all the Instagram sweeps available. I save the ones I want to enter. Then I enter just one an hour or so. This seems to help me avoid the lockouts. I hope this is helpful.