FreeCAD (FreeCAD) errors

26 recurring problems engineers report in FreeCAD (FreeCAD), ranked by impact.

#11 by errors trackedMCAD

Recurring FreeCAD (FreeCAD) errors, by impact

  1. 1FreeCAD STEP import does not recognize identical objects.MCAD · Agent failure · 1 report82
  2. 2A FreeCAD CAM deburr operation looks successful but only deburrs a small segment of a 51.6 mm B-spline edge, saving one short G3 move, because a point-coincidence check fails against a tolerance tighter than the job's 0.01 mm.MCAD · Agent failure · 1 report74
  3. 3A pocket operation sometimes drops its final depth pass, producing 3 Z layers instead of 4.MCAD · Agent failure · 1 report74
  4. 4FreeCAD writes raw non-ASCII characters into AP214 STEP files instead of the spec-required escaped form, so a part named in Korean or Japanese or with pi opens in FreeCAD but is refused or shows broken names in several commercial CAD tools.MCAD · Agent failure · 1 report74
  5. 5The machine editor and docstrings say a rotary axis parent is the axis it is mounted on, but the rotation math and factory templates read it the other way round. On a B/C head whose C carries B, any work plane that needed C failed to solve, the post refused it, and the simulator turned the part instead of the head.MCAD · Agent failure · 1 report74
  6. 6Through the Python API the pattern is valid and Up-to-date, but the Body's shape doesn't include it, and the next feature lands before it. GUI users are fine. Scripts and macros get bodies without the mirrored geometry, so exports and mass come out wrong.MCAD · Agent failure · 1 report74
  7. 7When a script or macro passes a face from an earlier feature, the new Thickness becomes the Tip but bases itself on that earlier feature. Everything between silently drops out of the Body shape, and the new feature still shows Up-to-date with no error. The reporter calls it easy to miss, and it hits exactly the path agents use (Python, face names captured before later edits).MCAD · Agent failure · 1 report74
  8. 8A material the file referenced but the machine didn't have caused an "Invalid Document.xml" error with what the maintainer calls dramatic consequences. It came from a user's file on the FreeCAD forum, and the fix currently sits in a Codeberg fork. One missing library entry takes down the whole model, not just the material.MCAD · Agent failure · 1 report66
  9. 9A part driven by expressions from a central part library started crashing randomly on open and recompute, apparently through the cross-document link.MCAD · Agent failure · 1 report66
  10. 10a PartDesign Pocket whose sketch shares coincident edges with existing walls fails OpenCascade's boolean at the default 1e-7 tolerance and the whole body disappears from view; the workaround is hand-offsetting the sketch 0.01 mm inward.MCAD · Agent failure · 1 report66
  11. 11a script that deletes TechDraw pages to rebuild them races the background view recompute, and FreeCAD aborts with no message and loses unsaved work.MCAD · Agent failure · 1 report66
  12. 12A SolidWorks user builds project boxes around several ready-made boards. They used one sketch per board with the outline as construction geometry and aligned each new sketch to the previous outlines. FreeCAD hides construction geometry in visible sketches, so board placement and relative constraints don't work. The PCB outline as a shared reference for the enclosure is the real need here.MCAD · Agent failure · 1 report66
  13. 13A user asks that mates and attachments show up and edit through the same interface and tree, because with a mix of both "where could I see these relation." Relationships between parts are split across two systems inside one CAD tool.MCAD · Agent failure · 1 report66
  14. 14An assembly distance joint correct in FreeCAD 1.1.4 now shows over-constrained in 26.3rc2. Same file, new version, the solver reports the joint over-constrained. A small version-migration break with a repro file attached.MCAD · Agent failure · 1 report66
  15. 15Every recompute of a PartDesign Pad piles more geometry onto the same topology, slowing previews from 415 ms to 950 ms after 20 drags.MCAD · Agent failure · 1 report66
  16. 16For some large drafts on rounded corners, OCCT returns an invalid solid. The Draft feature reports success, so later features are built on broken geometry. The PR makes it error out. The root cause is still open in OCCT.MCAD · Agent failure · 1 report66
  17. 17FreeCAD 26.3 RC2 regression: files saved in 1.1.x with å, ä, or ö in the name throw Unknown document errors in Sketcher until renamed.MCAD · Agent failure · 1 report66
  18. 18FreeCAD 26.3 RC2 regression: splitting a line in Sketcher now ties the halves with a tangent constraint where 1.1.4 used coincident.MCAD · Agent failure · 1 report66
  19. 19FreeCAD CAM facing leaves material in the middle of the part.MCAD · Agent failure · 1 report66
  20. 20FreeCAD crashes when a sketch constraint is changed, per the smaller-stuff mention in the afternoon Haitch pass.MCAD · Agent failure · 1 report66
  21. 21FreeCAD STEP colour export breaks in a non-English UI because export silently fell back to the plain Import module and dropped colors.MCAD · Agent failure · 1 report66
  22. 22In 26.3 RC2, a scaled Draft clone shows 1.0/1.0/1.0 in the task pane while the properties pane shows 1.2/1.2/1.0. Two views of the same object disagree, and 1.1.4 did not.MCAD · Agent failure · 1 report66
  23. 23PartDesign Linear Pattern and Mirror ignore a Pocket's Operation=Common and replicate it as a subtraction.MCAD · Agent failure · 1 report66
  24. 24since the August crash reporter, importing FreeCAD as a Python module replaces signal handlers the script already set, so pausing code in the Pyzo IDE kills the whole process and writes a crash report.MCAD · Agent failure · 1 report66
  25. 25the BIM door tool inherits from the window tool and shares its preset list, so adding a preset desyncs the index mapping and the user gets the wrong thumbnail and wrong parameters depending on which command they used.MCAD · Agent failure · 1 report66
  26. 26The same STEP file imports with unexpected toroidal protrusions in FreeCAD 1.x that were not there in 0.21.2, and the reporter links three older STEP fidelity issues across versions. Geometry trust depends on which version of which tool reads the file.MCAD · Agent failure · 1 report66

How it fails

  1. Agent failure26

Engineering tools that address these errors

Sourced from public community reports. Costs and delays on individual entries are modeled estimates, not measurements.