Phone freezes when turning on the wifi icon

[Kenten1993]

Hi, I have had my LG Optimus M plus, for a while now and sometimes when I try to use Wifi after I have used my data, my phone always seems to freeze up on me and it's kind of getting annoying. Can anybody help me out with a solution to this problem? I have a battery saver app that lets me turn wifi on but I need that battery saver and I do not access Wifi though that app. So help. Please.