Z-Axis homing error

Hi All.

I have had my Taz 6 for about 3 years and it has been running well. Recently,i noticed that it seemed to be loosing the z offset, almost smearing the first layer. I reset the z offset and ran a print and all seemed well. I went to run the print again after making an adjustment to the z-offset again and I received an error. The printer ran through the normal startup, homed x and y, then heated to 170 and moved tot he z axis switch, and ran a cleaning function but at 1/2 inch above the cleaning pad. I shut off the printer and restarted after about thirty seconds.

I started the cycle, the printer ran through the x/y home and then the z axis moved to about a half an inch of the z-axis switch and then reversed direction and flashed an error.

Any ideas on how to correct this? I am currently using S3D for a slicer for the Taz 6.

As an addition, for the past 6 months or so I have had to turn the Taz off after each print or it would start a new process about half an inch above the cleaning pad (would give a cleaning failed error).

Update you start gcode based on the new commands found in the most recent cura profiles. The newer firmware needs extra commands to avoid problems with bed leveling.