AppEngine Login Issue

Hello Mitch and Yaw,

I have a problem logging into the ODK Aggregate server. I set up the server yesterday and it worked perfectly. I enabled billing as well. However, when I tried to access it today, it responded with AppEngine Application Problem. I checked quotas section and they were not exhuasted. However, when I check the logs I found the following error:

I have added you as a developer to take a look. Your support is highly appreciated. Thanks!

What version of ODK Aggregate are you using?

I am using version 1.4.15.