I also had the same problem when I run spyder or anaconda-navigator. I have tried many solutions suggested, but only Khoward's solution above helped me. It is as below.

export QT_XCB_GL_INTEGRATION=none

The problem is that when I reboot my ubuntu, I had to run the script above again. So, I opened

nano ~/.bashrc

and added the line below at the bottom of the file.

export QT_XCB_GL_INTEGRATION=none

Saved the file(Ctl+x).

And rebooted and running spyder and anaconda-navigator was ok. I think it was the problem caused by between QT and OpenGL.