We are upgrading our fleet of routers, well over 400 of them now to the latest bugfix of 6.42.9 from 6.40.8. I would like to say that we’ve had no failures on 2011,751,951 and I’ve done one tile. We have had 7 failures where the router doesn’t upgrade. It can be fixed with a netinstall so I consider this a soft brick. The affected ones are and HEX series (mmips and mipsbe) and Powerbox (Mipsbe). The only thing that I can correlate between them is the flash size. We run the same configs on all the routers that have been affected. It’s not every time we have a problem but its making upgrades difficult to do remotely. I can also state that when we moved from the bugfix prior to 6.40.8 we had 3 failures and I chalked them up to flukes. Two of the seven went into boot loops and the others would power up and the ethernet light would blink but the router wouldn’t beep. Resetting the config on one hex (mmips) about 5 times and the router booted with no config. Just the old 0.0.0.0. The others I just netinstalled and restored the config. I’ve got two powerbox’s left that I haven’t done anything with if Mikrotik needs to see one.