How do I add a second Google Apps account to my Nexus 9? I'm trying to add my school Gmail account to my new Nexus 9 tablet. The OS is 5.0.1. The account is a Google Apps account. I've entered another Google Apps account without a problem. After I enter the username in the "Add account" screen, I hit Next. The password screen goes white, with no button or fields. 

Does anyone have any idea how to fix this?
I ran into this issue after updating to Android 5.0 and reported the issue to Google. I was promptly told "it's a known issue, but no ETA on fix". I ultimately resolved the issue for me, using this process below. I hope it helps you!

I was trying to add an account (from my school) that used web-based authentication for Google apps. After running adb and trying to add the account, I captured the following error when the white screen was displayed:


  I/GLSActivity( 5367): [AuthUrlChecker]Untrusted Auth URL: \http://my.pcc.edu/ProcessResponseServlet
  I/GLSActivity( 5367): [AuthUrlChecker]Untrusted Auth URL: \http://my.pcc.edu/ProcessResponseServlet
  I/GLSActivity( 5367): [AuthUrlChecker]Untrusted Auth URL: \https://my.pcc.edu/GoogleAltLogin-2.0.7/GoogleRedirect.jsp
  I/X509Util( 5367): Failed to validate the certificate chain, error: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.


I visted the url "https://my.pcc.edu/GoogleAltLogin-2.0.7/GoogleRedirect.jsp" in Chrome on my desktop, and noticed that there were no certificate issues (go figure!). I used Chrome to view the certificate trust chain for the website, and compared this to the certificates installed by default on my Android 5.0 device (go to Settings->Security->Installed Certificates->System to get list). 

I noticed one certificate that was missing on the Android device, "VeriSign Class 3 Secure Server CA - G3". Google Chrome on the desktop thinks this is trusted, so I exported just this one certificate using Chrome, and saved it in the DER-encoded format with a .cer file extension. Then I copied this to the Android device and imported it into the certificate store (Settings->Security->Install from Storage). After doing this, I was finally able to add my Google apps account that uses web authentication!