Prusa error 13613 (File System Error) appears on the MK4 and its equivalents are #26613 on the MK4S, #21613 on the MK3.9, and #23613 on the MK3.5. The printer detected an error in its internal file system — the storage layer that manages configuration files, calibration data, and other persistent settings.

What the Error Means

The Buddy board’s internal flash storage uses a structured file system to organize settings, bed mesh data, and print history. A file system error indicates that the firmware encountered an inconsistency when reading or writing this storage — possibly an interrupted write operation from a previous session that left a file in a partially written state, or an underlying flash memory defect. The error can appear at startup (when the firmware mounts the file system) or during a print (when settings are being saved). A single occurrence is often transient; repeated occurrences suggest actual storage degradation.

Step-by-Step Fix

1. Restart the printer. Many file system errors are caused by transient state left over from a previous session and clear on a clean reboot.
2. Update firmware to the latest version. Firmware updates include file system driver improvements that can resolve inconsistencies introduced by format changes between versions. Download from prusa3d.com/drivers.
3. Perform a factory reset. Navigate to LCD Menu → Settings → Factory Reset. This reformats the internal storage, clearing any corrupted file system structures. Note: all calibration data, settings, and print history will be erased. Re-run First Layer Calibration and all other calibrations after the reset.
4. Contact Prusa Support if the error recurs after factory reset. If the file system error returns immediately after a factory reset, the underlying flash memory is likely failing and the xBuddy board may need replacement.

Parts Required

• No replacement parts are typically required for this fix — basic tools only
• Replacement xBuddy board (if flash storage is confirmed failing — contact Prusa Support first)

If a factory reset does not prevent the error from returning within one or two boot cycles, contact Prusa Support at help.prusa3d.com for board-level diagnosis.

Frequently asked questions

What does Prusa 13613 mean?

Prusa error 13613 (File System Error) appears on the MK4 and its equivalents are #26613 on the MK4S, #21613 on the MK3.9, and #23613 on the MK3.5. The printer detected an error in its internal file system — the storage layer that manages configuration files, calibration data, and other persistent settings.

How do I fix Prusa 13613?

Prusa error 13613 means an internal file system error was detected. Learn how to restart, update firmware, and factory reset to clear storage corruption on MK4-series printers.