Posted by: @eef

I think I can help you there. Last week I upgraded my MK2.5S with a revo six nozzle. 
I contacted Prusa Support with your same message/question. This is the advise (and it works up to now without any error). 

1. Upgrade the MK2.5 with latest firmware 3.13.3. Once you have flashed and updated your printers firmware Run both the PID and TM calibration from the LCD Calibration menus of your machine. (I only did the PID!)
2. goto https://github.com/prusa3d/Prusa-Firmware/issues/4451 
read and download reset_revo.gcode.txt or reset_revo_hf_60W.gcode.txt for Highflow nozzle
upload it to sdcard; change to *.gcode (delete .txt) ;insert into printer and run the file. 
3. You get some messages and questions, just proceed and after 1-2 seconds it is done. No endmessage. (I did it a couple of time to see if I had missed something, but no, it just stops). 
In the file are settings what set the enviroment as wanted by the Revo. 

When done, you are good, no temperrormessages and still enough protection . 

I'm about to install a Revo Six on my Prusa MK2.5S with FW3.13.3 and have a few questions . 

ad 1 : you wrote: ( I only did the PID!). As far as I understood the TM calibration option is not implemented in the FW3.13.3 for the MK2.5S , so even if you wanted to.......... ( at least , I couldn't find the option under Callibration in the LCD menu, but please correct me if I'm wrong)

ad 3 :You wrote , that after running the file reset_revo.gcode  you're done and good to go , but  I read the instructions on https://github.com/prusa3d/Prusa-Firmware/issues/4451  for the reset_revo.gcode and there it says: 

5. Once the G-code has been installed re-run both a PID and TM calibration from the LCD Calibration menus of your machine.

I didn´t find that in your instructions . Is it not necessary to rerun PID callibration ?   ( again , the article on the Github site  was written for the MK3, so there TM calibration makes sense, not for the MK2.5 )

Thanks 

Thanks again. 

1. Upgrade the MK2.5 with latest firmware 3.13.3. Once you have flashed and updated your printers firmware Run both the PID and TM calibration from the LCD Calibration menus of your machine. (I only did the PID!)
2. goto https://github.com/prusa3d/Prusa-Firmware/issues/4451 
read and download reset_revo.gcode.txt or reset_revo_hf_60W.gcode.txt for Highflow nozzle
upload it to sdcard; change to *.gcode (delete .txt) ;insert into printer and run the file. 
3. You get some messages and questions, just proceed and after 1-2 seconds it is done. No endmessage. (I did it a couple of time to see if I had missed something, but no, it just stops). 
In the file are settings what set the enviroment as wanted by the Revo. 

When done, you are good, no temperrormessages and still enough protection . 

Summary

• Fixed Ghost layer shifts
• Improved XYZ calibration
• Prevents false positive “File incomplete. Continue Anyway?” messages.

This is the stable release of firmware version 3.13.3, with a primary focus on fixing the ghost layer shifts found in the previous firmware release.

We would like to apologize that it took so long to find the issue/bug and fix it.

Please, read the change log v3.13.2...v3.13.3 and Milestone FW 3.13.3

This firmware version only works correctly with MMU2S/MMU3 firmware version 3.0.2! It is necessary to update the firmware in the MMU2S/MMU3!

Fixed Ghost layer shifts

Short summary: In firmware version 3.13.2, the XY axis currents were incorrectly configured and they were not switched to running currents after homing. This is now fixed.

Detailed overview:
We received several reports on Ghost layer shifts from the community, but we couldn’t reproduce these issues on any of our internal 3D printers.

Eventually, we found a printer on which we could reproduce this issue. However, it wasn’t consistent. Sometimes, the printer worked just fine and the Ghost layer shifts appeared randomly. This is why the fix took longer to prepare. We had to analyze the issue from multiple perspectives and kept testing various approaches. Although we received a number of reports from the community, we couldn’t find a single common denominator. For example, some reports claimed that the only stable firmware was as far as 3.11.0, while others claimed that the system is still stable on FW 3.13.1, etc. Moreover, most final releases contain hundreds of changes/commits which makes it even harder to find the needle in the haystack.

Eventually, we found out that we needed to focus on FW 3.13.2 because with FW 3.13.1 we have not seen this happening. The changes between FW 3.13.1 and FW 3.13.2 still have 227 commits and 114 change files but compared to FW 3.11.0 → FW 3.13.2 with 2125 commits and changed 805 files, this was an “easy” task to find the cause.

Homing needs lower currents to reliably find the home positions.
The lower currents on the XY axis caused Ghost layer shifts in some printers. These currents are necessary for precise homing, therefore, they need to be switched to regular currents for proper operation. We have identified and fixed the cause in this release.

Improved XYZ calibration

After the 4th point of XYZ calibration of the bed, the X gantry raises up and waits for user interaction to place the sheet back on the bed to continue with the MBL. When there was something under the sheet or nozzle, the previous versions have pushed the nozzle into the sheet or bed.

Now the printer firmware moves the Z axis less aggressively downwards and checks if the PINDA triggers. It also detects obstacles on the bed and displays an error before starting to search the MBL points.
When the sheet is empty, there is no substantial debris on the nozzle and the PINDA is working correctly, the nozzle shouldn’t be pushed into the sheet anymore.

False positive “File incomplete. Continue Anyway?” messages prevented.

Newer PrusaSlicer versions create larger G-code files than previous versions. This exceeds the limits of the Prusa 8-bit firmware checking for M84. We increased the value from 20000 to 30720 so even large G-code files shouldn’t cause false trigger.

Please report any bug here:
https://github.com/prusa3d/Prusa-Firmware/issues

Download Link:
https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.13.3

How to flash the firmware:

https://help.prusa3d.com/en/article/firmware-updating-mk3s-mk3s-mk3_2227