Got this new K1 Max last September. Never had any real issues with it until today when the printer just stopped after printing for a couple minutes with a special message for me…
I found the support page where it explains what I need to do… 
I’ll have to check it out later when I get a chance. Maybe something shook loose…?
Any one else have this error pop up.? And what caused it…?
Does the thermistor thing ever burn out…?
Maybe it’s time to get a Micro Swiss hot end…???
Did yours come with a spare hotend too?
Most common issue is a broken contact of the heater or thermistor but it’s hard to fix it in most cases and just can be replaced. You could remove it and try to see if the issue can be located with a multimeter, but if it’s close to the heating element you can’t really solder it.
Thanks for the reply @s3sebastian… It did come with a spare and I had also bought some on Ali Express. I’ll probably replace it with that only because I have a lot of nozzles that will fit and I won’t be able to use them for a micro swiss…
Update for my fix for the #2564 error in case anyone has this error on a K1 Max or possibly K1 …with the original hot end…
This thermistor plugs into the hot end to regulate temperature.
When it’s not working correctly the machine usually throws the 2564 error. ( sometimes I’ve seen other numbers. )
When I took the thermistor out. (held in with a set screw) I noticed some white powder in the hole…? that I had to clean out. Not sure if that was causing resistance which resulted in the incorrect readings… ??
That is the hole where I had to clean out that powder. The thermistor fits into that and is held in place with a set screw.
Anyways to make a long story longer I replace the thermistor, put it all back together, recalibrated and it’s back printing great… 
