I’m sorry to hear that this hasn’t been resolved for you. Are there any crash report files in the following location? If so, it would be helpful to upload them here C:/Users/YOURNAME/AppData/Local/Temp/Eleventh Hour Games/Last Epoch/Crashes
Unfortunately, if your computer is restarting without any warning it sounds like it could be a hardware related issue. I would recommend trying to run the game without any overclocks or voltage changes on your CPU and GPU, and disabling XMP for your RAM.
Please let us know if that helps.
If this still happens without any overclocks or XMP, the problem could be related to your computer’s power supply. However, I recognize that it’s not very practical to try replacing that and hoping that’s the problem.
Also, thanks for linking to troubleshooting information @rudreais , I appreicate it.