If the Nouveau driver is not disabled, the Linux OS may be suspended and the ECS may not be remotely logged in to. This issue generally occurs when you use your own private images (exported from ECSs or other sources).
dmesg | grep error

lsmod | grep nouveau

If the /etc/modprobe.d/blacklist.conf file is unavailable, create one.
vi /etc/modprobe.d/blacklist.conf
Add the following statement to the end of the file:
blacklist nouveauoptions nouveau modeset=0
sudo update-initramfs -u
mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.bak
dracut -v /boot/initramfs-$(uname -r).img $(uname -r)
reboot