Stuck on loading page and servers return error 501

[swagzhang]

Dear Mr. Ranaut,
I am trying to build your skooter project now. It has been two days already. I got stucked on a 501 error when I tried to get through the loading page of the app. I stucked on the loading page like forever. Of course, I could change some code in java to walk around this, but I really want to figure out what goes wrong here. Please help me! Thank you so much. https://mail.google.com/mail/u/0/#sent/QgrcJHsBqLqFCCPRbqrjJgXKWzqjnzCgtxV?projector=1&messagePartId=0.1

[swagzhang]

Started POST "/api/v1/user" for 199.195.129.180 at 2018-07-20 21:50:31 +0800
ActiveRecord::SchemaMigration Load (0.3ms) SELECT schema_migrations.* FROM schema_migrations
Processing by UserController#create_user as HTML
Parameters: {"device_info"=>"HUAWEI MHA-AL00", "phone"=>"c50cdf21498df66a", "android_version"=>"26", "version"=>"v1", "user"=>{}}
Unpermitted parameters: device_info, phone, android_version, version, user
User Load (0.2ms) SELECT users.* FROM users LIMIT 1
(0.1ms) BEGIN
(0.1ms) ROLLBACK
(0.1ms) BEGIN
(0.1ms) ROLLBACK
Completed 501 Not Implemented in 46ms (Views: 0.3ms | ActiveRecord: 1.5ms)