Sometimes the installer crashes. With 19.10, this happened when trying to connect to the wifi. The solution is to set the kernel parameters when starting the installer or live environment.
- Press
e
when the grub boot menu is displayed (the menu that lets you "Try Ubuntu" or "Install Ubuntu") - On the line containing the kernel parameters, add the following (to the same line) after
quiet splash
:acpi_rev_override i915.modeset=1 nouveau.modeset=0
Note: I'm not sure if they are all needed, but it fixed the installer from crashing when connecting to the wifi.