Is it possible to retrieve the last print location on fail/pause/

The printer is currently on pause, but I had to restart octopi server due to a server error, is there a log on the octoprint that saves the last layer, hot end position?

I would like to manually modify the print file to start printing at the current location.

There isn't really a way to know for sure. Best approach I've seen is measuring.

Great guide.
I was able to save and finish the print with following steps:

Some background information.
The printer is a Creality Ender 3 Pro with 4.2.7 board, filament sensing is controlled through Octoprint. The event that led to the failure was that during a long print, filament ran out caused the print to pause, however, I wasn't able to change the filament for several days, during which time, the time-lapse video continued to take images at 1sec interval. The temporary time-lapse images ultimately filled up the entire SD card that's 64 GB in size, rendering the Octoprint server unresponsive and eventually I had to manually remove all the temporary time-lapse jpgs, and restart the Octoprint server.

Luckily, the printer itself was unaffected; it could still resume and pause.

For what it is worth, I took below steps to rescue this print:

  1. Resume the print to release the serial port to Octoprint. This allowed me to send command M114 to retrieve the coordinates of the hot end, including layer height, e.g., Z:84.72
  2. Pause the print again on the printer
  3. Modify gcode file to start printing from the next layer (as suggested by the Youtube video)
    3.a Find the next layer after Z:84.72, which is Z:84.92 (0.2mm layer height)
    3.b Delete all gcode file from layer 0 and up-to (but not including) G0 Z84.92.
  4. Also modify Home axis from all "G28" to XY only, "G28 XY", and that's it.

Hello,
I do have a question about "filament sensing is controlled through Octoprint." How to you do that. I had that question posted here a view weeks ago and at Creality help desk, did not received any answer yet.
Willem

Search for filament sensor in the plugin repository

I use Filament Sensor Simplified.
The sensor used is home-made similar to this: https://all3dp.com/2/weekend-project-make-your-own-filament-sensor/

The COMMON is connected to GPIO 25, and the sensor output is connected to 3.3V.
Switch type is Triggered when open, but depending on how you wired up your sensor, it can be set to Triggered when closed.

Filament run out action, set M600 X0 Y0 E5 Z5

The FW needs to have filament run out sensing enabled. Good luck.