Wi-fi sign-in is required but the screen is blank. How can I enter my information?

[AC Question]

wi-fi sign-in is required but the screen is blank

I purchased a new HTC phone this weekend. My work Wi-Fi connection requires users to log on. The final step to log on screen on my phone is blank. There is a header at the top of the page that reads "Wi-Fi sign-in is required" and at the bottom of the page "enter your username and password to connect to this network" but middle of the page is blank. I am unable to enter the required information.