error about aothor

I just use the code below to check the environment
```
import time
import ai2thor.controller
controller = ai2thor.controller.Controller(port=5900,x_display="10")
controller.start()
print(f"Start Resetting")
controller.reset('FloorPlan28')
print(f"Start Initializing")
controller.step(dict(action='Initialize', gridSize=0.25))
for i in range(10):
print(f"Start stepping {i}")
event = controller.step(dict(action='MoveAhead'))
print(f"Finish stepping {i}")
time.sleep(1)

event.frame
event.cv2img
event.metadata
```
when I run this script, it present a error
```
MYLOCATION/site-packages/ai2thor/controller.py:1150: UserWarning: start method depreciated. The server started when the Controller was initialized.
warnings.warn(
Traceback (most recent call last):
File "test_ai2thor.py", line 10, in
controller.start()
File "MYLOCATION/site-packages/ai2thor/controller.py", line 1162, in start
self.server.start()
File "MYLOCATION/site-packages/ai2thor/fifo_server.py", line 202, in start
os.mkfifo(self.server_pipe_path)
FileExistsError: [Errno 17] File exists
```
After I remove the controller.start() line, it presents Start stepping {i} and Finish stepping {i} but there is no windows to show the picture.
What's wrong with that? I just use a realVNC viewer to connect my server(with virtual desktop), so should I change some config? (ai2thor==3.1.0)