Hotend preheat error

I observed the same behavior today with my MK4s with MMU3. I updated my MK4 to an MK4S a few months ago. Single prints without multicolor change run cleanly. But now I wanted to make the first print with color change today and after about 1 hour I always got the error. I can rule out technical errors as it otherwise works perfectly with normal printing. Is there a remedy in the meantime or should I contact support?

I just completed my upgrade from 3s to mk4s.
I am getting this warning. I double checked and made sure the hotend thermistor wasn't plugged into the heartbreak spot. Tried again and the error continues. Attempting basic continuity tests for the hotend and thermistors didn't cause the piezo speaked in my innova to go off so something is strange.

Same as some others here I go that error after installing a MMU3 on my MK4. During testing it was noted that the temperature was lowered by 20 Deg. C just prior filament change while printing on the tower. Afterwards the temperature order was back again to printing temperature, but the actual temperature raised too slow, leading to print on the object on temperatures well below target temperature. That gap between target and actual temperature was small at the beginning of the print, and became bigger with each filament change. At some point, it seems that this triggered the interruption of the print and to the error message. Wires of thermistor and heater were inspected without visual damages, plugs were properly fixed at the lovboard. Printing with one color only tested without issues and errors. I lowered the fan speed to max. 40% to prevent fast cooling during filament changes. Two test prints after that change with multi (5) color prints were done sucesfull. My conclusion would be an underperforming heating element or,  on the software side there should be a hold point to wait for continue to print after filament change until actual temperature is within acceptable range. My MK4 was runnign for more than a year before installing the MMU3.  Did not find information about the life time / performance of the heating elemnt in relation to running hours and heating cycles.For a one color print, heating times are not from an interest, so perofmrmance of the heater will be not an issue until the heater is dead.

I received this error on the MK4S during filament changes after installing the MMU3. The first three attempts at a multi color print all failed. I had removed the sock and reinstalled it and that fixed the problem. 

Any fix for this yet? Only happens to me on multicolour prints and not always at the same colour change. Single colour prints work fine. I'm sure Prusa will fix this at some point but at the moment there's not a lot of information.