What happened?
If a Prusa Printer with a CoreXY detects a crash, the printer will attempt to find a reference point through a procedure called precise homing. If the right and left sides are not aligned, the precise homing will fail, and this error will be shown.
Error name: Precise Refinement Failed
Error code: #17102 (XL) #31102 (CORE One)
How to fix it?
Check the belt tension (Adjusting belt tension (CORE One) or Adjusting belt tension (XL)) and adjust it if needed. Ensure that the printer's right and left sides are perfectly aligned.
After correctly adjusting the belts, the two plastic parts on the sides of the rail should reach the front of the axis together.