1) Close Safari on your phone
2) Open the Settings App
3) Scroll down and select Safari
4) Scroll down to Privacy & Security and click Block Cookies
5) Make sure Allow from Websites I Visit or Always Allow is selected, if any of the top two options are selected it won't work.
Once that settings has been set hit the Back button in the top left and hit Clear History and Website Data to ensure your cache and history is cleared.
You might also have to Turn off you Private Browsing if it is on. To check if private browsing is on follow these steps:
1) On your iPhone, iPad, or iPod touch, open Safari, then tap .
2) While Private Browsing is on, Safari appears black or dark instead of white or gray. Make sure that it is off.
It should now work, if there are still issues email email@example.com.