I followed this video by Mockaroo https://www.youtube.com/watch?v=H91_P_Zr2M0. I followed exactly what the video tell me to do, and created an API for testing.
But when I click on the link: https://my.api.mockaroo.com/users.json?key=bcc83090
I get the message error: **"Undefined method file_format' for nil:NilClass"**. How can I fix this problem? Thank you. **Solution**: I change the link name from Users.jsonto an unique name likemyuniquestring421.fson` fixed the problem
