Hi filipbielik,
Welcome to Sony Community!
We're sad to hear on what happened to your laptop. May I know what were you trying to do? The SVE171C11M is not recognized by our system. Please check the exact model name of your unit. What is the current operating system of your laptop? Did you try to reverse what you did on BIOS? ( you said I changed my boot mode from UEFI to Legacy) it started all here, right? If you haven't reverse it yet then do so afterwards replicate the issue.
Regards,
Jen
If my post answers your question, please mark it as "Accept as Solution"