mobile

Hi experts. Please help me. I have Nokia Lumia 822. I have Windows 8.1. Lumia Denim update, now i want install Windows 10 TP on my lumia. My phone is officially supported for technical preview. I installed Windows Insider App from Windows Phone Store and when i opening app and clicking on "get preview build " insider app close automatically. ( i can not choose <enroll> slow and fast mode) What's happening? My friend has Same mobile but everything is fine. I reset my phone but nothing. i registered on Windows Insider program. Everything is correct but i have this big problem. Please help me if you can. ( this problem also i found on Windows Insider App feedback) please help me. Thanks,