Hello, I've got myself a pretty old VEMS v3.3 unit that I'd want to upgrade firmware-wise to use the LSU 4.9 WBO2 sensor. I have already soldered in the 27k resistor for the nernst voltage now it measures around 5v (before it was under 4v) and then I realized my firmware is too old to support it, it has the old type bootloader so I cannot update the firmware past certain version so I'm trying to upgrade it. I have already made myself a BSD cable and reprogrammed the ISP to lock the fuse bit and installed the correct firmware for bootloader upgrade and I only need the password for bootloader upgrade authorization, I have contacted both through the website contact form and sent the email to info@vems.hu stating my serial number asking for the password request and about a week has passed and I haven't got any word back, do I have to write it in a specific way to get a response or are the offices currently closed because of the coronavirus pandemic? Also speaking of the serial number, if VemsTune says my serial number is SerialNumber: v3.3_n003125 then I have to state that my actual serial number is 3125, the last 4 digits, correct? And if I cannot get the authorization for bootloader upgrade and get the correct newer firmware for whatever reason can I still somehow get the LSU 4.9 to work with the older firmware? Thanks in advance, I hope somebody can help me