FINAL OUTCOME - I loaded the v2.94 swu file (the v2 one and 1 version on from the 2.93 files I was using) onto one of the new USB sticks and it ran as it is supposed to; all three displays are now updated. I followed the same process as before but the combo of using the v2 file on this particular USB stick seems to be what it wanted. NO IDEA why this worked while the other combinations did not. Doesn't seem a very robust process overall. Thank you everyone for your help - it's much appreciated.
UPDATE: I finally got my hands on two brand new USB sticks; put the CANvu swu file on them and inserted them. The display said no software file found, same as before. That's now 5 different USB sticks. This should be the easiest thing to do and it's driving me crazy. How do I get a straight answer from Victron as to why three of their CANvu display units will not update by USB? If it's something I'm doing wrong then great (because my displays aren't stuffed!). All I'm doing is downloading the swu file to the freshly formatted USB stick, navigating the display to "update firmware using USB" and inserting it in the back. What else should I be doing?
Original post below ...
I have seen two other questions about this and neither got an answer - hoping for a better outcome!
I have 3 CANvu displays and I'm getting an Error 25 - firmware incompatible fault since updating the firmware in my Quattros (48V/5KW), although only on the port side for some reason, despite the starboard side being identical.
My CANvu displays are at v2.61 (2020) and the latest version is v2.93. The issue is that I put the USB in the back of the display with the .swu file on it and it doesn't recognise it - says "no firmware file found" or something like that. I have tried 3 different brands of USB sticks.
I actually doubt the display is recognising the presence of a USB stick because I don't get the message about data logging that you're supposed to. I also don't get the extra option in the display to safely remove the USB although I do get the message when I pull the USB out that it was removed incorrectly.
Any suggestions for how to update the firmware would be appreciated - thank you in advance.