Ubuntu18.04 NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver

when I run command nvidia-smi, it reports:
NVIDIA-SMI has failed because it couldn’t communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.it

I have got the nvidia-bug-report.log.gz, but when I uploading here , it told me don’t support this format.
How to give you the bug-report file to you to help me slove this problem?

just add .log at the end to upload.

I think I face the same problem