Turning ACPI off on a mobile PC (laptop/notebook) is not a good idea - it disables all power management you really want on those devices.
The root cause is probably a 'broken' BIOS that presents a false, corrupt or confusing ACPI table to the kernel. It may have been noticed by others and a workaround could be available. Also, your laptop vendor may have fixed this.
Some options I see you have from here (in your now somewhat vague but general situation):
Note that the kernel in the image to install Ubuntu is older than what is now 'stable', as some updates have been made available after the release. First thing to try is to apply all system updates and temporarily remove the boot parameter. Boot into Grub holding Shift, select the right entry, press E, remove the
acpi=off kernel parameter and boot with F10. Keep using this with all options below to try!
Try to boot with
acpi_osi=Linux as kernel parameter.
Upgrade to a more recent kernel. See this answer on how to do that.
Try to see if your laptop vendor has a BIOS update available. Apply it if so.
Try to boot with just one graphics card. Disable the discrete/Nvidia one and try also with the integrated one disabled.
In case you have an Nvidia Optimus enabled machine (hybrid graphics, often found in laptops), try to install Bumblebee for proper support of this technique. You can find some instructions in this answer.
Try to see if you have OS/ACPI specific settings in your BIOS.
Google around using your device vendor/type combination together with the keyword 'Linux'. Another distribution may have fixed it, someone may have proposed it to the kernel developers, but it may not have been merged in the main kernel tree yet, etc.
Report it as a bug. How do I report a bug?
Once you've managed to fix the issue, remove the kernel parameter permanently by removing in from the file
/etc/default/grub and running
sudo update-grub. (And if your solution was to boot with another kernel boot paramater, just edit the
GRUB_CMDLINE_LINUX_DEFAULT setting accordingly in that file.)
If you have more specific information on that and need assistance, make it a new question, e.g. "How do I apply this workaround for my HP Probook... ?"