Got error 500 internal server error with 'AttributeError: 'NoneType' object has no attribute 'get'' when access the site I've created.

[koalawangyang]

I've followed the instruction to create the website: frappe.cedim.cn , but always get the error 500 internal server error.

I've tried to uninstall and re-install this app for several times. All failed by this error.