7i76e was working, now CR1 LED does not go off

Its what I would expect...

Why are you attempting to write the fallback configuration?
( This should really never need to be done and you don't want to
write a standard config to the fallback area either )

If you want to update the firmware, the command would be:

mesaflash --device 7i76e --write 7i76e_7i76x1D.bit
then a power cycle or
mesaflash --device 7i76e --reload

Because I clearly didn't understood when to use the fallback region and therefore followed the guide I linked to earlier - This guide said "When we try to flash a new bitfile onto the board we first try it in the fallback region. Let's flash the new 5i25_7i76_7i85s.bit bitfile and try if it works." This is apparently NOT the way to do it.

Anyway - it worked! The board now initializes correctly and CR1 goes off when I start up Linuxcnc.
Thanx alot!