NVIDIA Graphic card stops working after pretest boot 1.23 hotfix2

[vonDatuh]

hi there,

i stumbled upon something strange and annoying.
i want to encrypt my system partition.
as soon as the pretest ist done my second monitor stops working. device manager says that my nvidia card has been deactivated due to an error (code 43). (?)
now...
when i decrypt the system partition the error is gone and my second monitor is back to normal and works flawless.
the bios uses "nvidia optimus"
nvidia driver version: 388/ 20.12.2017 (downloaded via lenovo systemupdate)
I tested this numerous times with different driver versions up to 411.95. always the same outcome.
secure boot on and off

Hardware: lenovo w530, win 10 pro 1803, nvidia quadro k1000m, veracrypt 1.23 hotfix 2, efi bios

Whats the issue here?

thank you for your time and this great piece of software

daniel

[Kevin Locke]

I just experienced what I think is the same error on a ThinkPad T430. For me the error only occurs when booting in UEFI mode with Compatibility Support Module disabled in the pre-boot configuration (fka BIOS Setup), so enabling CSM is a possible workaround. I also opened veracrypt/VeraCrypt-DCS#17 to track the issue.

[Mounir IDRASSI]

Thank you both for this report and sorry for the late feedback.
I have written a reply on the Github issue filed by Kevin.
Basically the issue is probably caused by clash between the memory ragion used by VeraCrypt BootLoade and the one used by nVidia device. This is reinforced by th fact that Kevin noticed that the issue doesn't occur if the nVidia card is configured so that it is exposed only to the OS and not EFI (in his BIOS, this accomplished by setting pre-boot configuration to "Discrete Graphics").

In our side, we used standard EFI functions to allocate the memory range to use and we don't know what memory range nVidia device is expecting to use. So for now, we can't do much and the best solution is to disable nVidia card in EFI and expose it only for the OS.