I successfully got rid of the blue triangle of death on my 265

I felt somewhat better seeing that other people were having the same problem, that it wasn't just me and that there were fixes.  These were the instructions that worked for me. It took me a few tries of releasing the correct buttons at the right time, but I finally got it.  I had to re-enter information, but that is small compared to worrying your watch won't work again!

support.garmin.com/.../