Hi Pablo, I'm seeing the same thing on a Chromebook "Pixelbook" Crostini (Linux) container:
Debian v9 ("stretch"), Linux kernel 4.9.0-12, recently updated. The system has 8GB RAM & 128GB SSD. The ChromeOS version in 81.0.4044.141. I'm running the latest Pharo Launcher, 2.0-2020.04.07, VM 5.0-202002121043. Just opening Pharo Launcher, and without even launching an image, I'm seeing the same tearing and rendering problems as Jan. If I open the Settings dialog, it partially renders, and when I try to move the window, I get the tearing behavior. And I was also able to run PL & images on this platform without problems in the past. (It's been at least a month since I tried running Pharo on a Chromebook.) -Ted -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html