iOS 8.4 causing my phone to lock up!

[iMore Question]

Thebios 8.4 is causing my 5S to lock up! I can't open my email, even the dial pad locks up! Can I do grade to last update, reinstall 8.4? Any suggestions will be appreciated. I can't find anything online! Help? Not sure how to fix!

 

[pr1nce]

Try doing a clean install of 8.4.