X Error of failed request: BadRequest (invalid request code or no such operation)

[JacobianTang]

I am so sorry.when i run this code ,i got a error!

X Error of failed request: BadRequest (invalid request code or no such operation)
Major opcode of failed request: 149 (RANDR)
Minor opcode of failed request: 8 (RRGetScreenResources)
Serial number of failed request: 14
Current serial number in output stream: 14

tips:
I run this code use vncserver.