nvidia Tesla K80 24 Gb GPU CUDA 9.1 toolkit installation on linux Redhat 7 on GUI base.

When I have installed Cuda 9.1 (cuda_9.1.85_387.26_linux.run) toolkit on RHEL 7 linux. Server is not starting in GUI. It is only starting in CLI. It means graphics drive is not loading. Please provide sutiable soluition.

Please run nvidia-bug-report.sh as root and attach the tar.gz file it creates to your post.