Hello,
As a new user to Unraid, I have been trying to get this working and install the ComfyUI Impact Pack. For any other noobs like myself, the fix that worked for me was opening the console of the docker and running the following:
sudo apt-get update && sudo apt-get upgrade
sudo apt-get -y install libgl1-mesa-glx
sudo apt-get -y install libglib2.0-0
The Github https://github.com/ltdrdata/ComfyUI-Impact-Pack specifies that both linux packages are dependencies so I just installed both to make sure.
Error went away afterwards.
Hope this helps.