FAQ & Troubleshooting

This page covers the most common issues encountered when uploading and processing STEP files in LOP, along with practical steps to resolve them.

Upload Issues

My file exceeds the 250 MB limit. What should I do?

Large STEP files usually contain geometry that is not necessary for load planning. The optimizer only needs the external bounding shape of the item — internal cavities, thread representations, weld details, and fine surface textures add file size without improving packing accuracy.

To reduce file size in your CAD tool:

1. Suppress internal features — hide or suppress anything not visible from the outside (internal ribs, hollow chambers, mounting holes smaller than 5 mm)
2. Remove design features — threads, chamfers, fillets under 2 mm, and knurling can all be suppressed without affecting the bounding box
3. Lower tessellation quality — if your CAD tool tessellates the model during export, use a coarser setting
4. Export the shell only — some CAD tools let you export the outer surface as a single body instead of the full parametric model

Most models can be reduced to under 50 MB with these steps.

The upload progress bar gets stuck before reaching 100%

This usually indicates a network interruption. Try:

• Refreshing the page and re-uploading
• Switching to a wired connection if you are on Wi-Fi
• Trying a smaller version of the file to verify the upload pipeline is working

If the issue persists, contact support with the file name and size.

The upload completes but processing never starts

If the status remains "Queued" for more than 5 minutes, the processing job may have failed to enqueue. Try:

1. Refreshing the page — if processing has started, the updated status will appear
2. Opening the item and clicking Re-process if that option is available
3. Re-uploading the file

Processing Failures

"Parsing Failed" — what does this mean?

The geometry parser could not read the file. Common causes:

"Analyzing Failed" — the geometry was parsed but analysis failed

This is less common and usually means the geometry, while technically readable, cannot produce a valid bounding box or volume measurement. This can happen with:

• Open shell geometry — surfaces that do not form a closed solid
• Zero-volume geometry — sheet bodies with no solid content
• Extremely large coordinate values — models with positions very far from the origin

Try exporting from your CAD tool with "Export as solid body" selected rather than surface or shell export. If the model is a surface model (not a solid), convert it to a solid before export.

"Tessellation Failed"

The solid was parsed and analyzed but the mesh generation failed. This is rare and typically affects models with:

• Very complex geometry (millions of faces)
• Degenerate faces with zero area
• Self-intersecting geometry

Fix: in your CAD tool, run a geometry check and repair. Most professional CAD tools have a "Check Geometry" or "Geometry Doctor" function that identifies and corrects these issues.

Processing appears stuck — no status update for a long time

If the status has not changed for more than 15 minutes, the processing job has likely timed out. Check the item status:

• If it shows "Processing Failed", the timeout was detected and logged
• If it still shows a processing stage, refresh the page — the status display may just be stale

To retry, open the item, scroll to the 3D Model section, and click Re-process or re-upload the file.

Geometry and Dimension Issues

The computed dimensions don't match the actual item size

The most common reason is that the CAD model is oriented at an angle relative to the world axes. The bounding box is always computed axis-aligned, so a model rotated 45° in the XY plane will produce a bounding box significantly larger than the part's true dimensions.

Fix: in your CAD tool, orient the model so its primary faces are aligned with the X, Y, and Z axes before export.

Another common reason is that the model includes packaging, fixtures, or assembly components that inflate the bounding box. Remove or suppress these before export if they are not part of the item itself.

If the computed dimensions are close but not exactly right, you can always edit the item manually and enter the correct values. The 3D preview will still use the STEP geometry, but the load planner will use your manually entered dimensions for collision detection and bounding box placement.

The 3D preview looks wrong or distorted

If the mesh is visible but deformed, inverted, or missing faces:

• The original geometry may have face orientation issues — some faces have reversed normals
• Try re-exporting with the "Heal geometry" or "Fix normals" option enabled in your CAD tool

If the preview is entirely missing despite the status showing Complete, try clearing your browser cache and reloading the page.

The model renders in the wrong color

By default, LOP applies the item's assigned color to the 3D model. If you uploaded a STEP AP214 file with color data and want to use those colors instead, edit the item and check the "Use CAD colors" option if available. Note that items with CAD-assigned colors may show multiple colors for different faces or components.

General Tips for Best Results

1. Use AP214 — it is more compatible than AP203 and carries color information
2. Simplify before exporting — remove internal features, threads, and fine details
3. Align to world axes — orient the part so its packing face is on the XY plane
4. Export as solid — use solid body export, not surface or sheet export
5. Verify in a viewer first — open the exported STEP file in eDrawings, FreeCAD, or a similar viewer to confirm it looks correct before uploading to LOP
6. Keep files under 100 MB — processing is faster and more reliable at this size