Solved Robo 3d says the temp droped to much before printing even though it was at correct temp

So you need to find the real error. That "Printer stopped due to errors. Fix the error and use M999 to restart."
Is marlins brain-dead way of telling you an error has happened. It doesn't tell you what error (which is THE DUMB) so read all the way back through the console log until you find an actual error. My wild guess would be that the error is

"Temperature fell too much during print"

Which cancels the print.

Go make sure.

 

And if the error is the one I mentioned then understand that the user interface does not display the temperature as fast as marlin reads it. It is seeing a sudden spike (down) in temperature and kills the print even though a split second later it is fine.

This is caused normally by bad wiring to the thermistor or the thermistor is loose/out of place/moving around or the thermistor is damaged/cracked.

In rare cases it can be a bad board (like the RAMPS) but -- rare.

 

Nope. That error is always hardware.

The firmware is just telling you that the signal from the thermistor is not working 100% of the time.

 

One of those I bet.

 

Often this error will happen when you are starting a print because the extruder moved around (and the thermistor moved and had a spastic moment due to one of the issues I described above).