#Troubleshooting

#Meshes are missing

The robot loads but some parts are invisible, and Checks shows A-001.

Open the package root, not a subfolder. Choose the folder that contains package.xml (or a folder above it), not urdf/ or robots/. If Checks also shows A-002, this is the cause.
Include every package the robot uses. If the URDF uses meshes from another package — a gripper, a sensor — that package must be inside the opened folder (browser) or the workspace or Extra package roots (VS Code). Opening your workspace's src folder usually covers it.
Check the file exists. Select the link; the Inspector shows the exact path it looked for. Mesh files are sometimes not committed to Git, or are stored with Git LFS and not downloaded.
Check the format. STL, DAE, OBJ, glTF and GLB are supported.

#"Missing ROS package" or `$(find …)` fails

The package name in the path doesn't match any package.xml in what you opened. Check the <name> inside that package's package.xml — it can differ from the folder name.

#The robot doesn't appear at all

Look for an error message in the corner of the window — usually XML that doesn't parse or xacro that doesn't expand. The message says where.
Click Fit in case the robot is far from the origin or very small.
If the robot is very large or tiny, its meshes may be in millimetres while URDF uses metres. Check A-003 in Checks and the mesh scale.

#Xacro problems

An argument has the wrong value — set it under Xacro parameters in the Joints tab, or in Default xacro args.
"Skipped unresolved xacro expression" — one ${…} expression failed and was left out; the message quotes it. The rest of the robot still loads. Often harmless, as with optional TCP offsets.
load_yaml fails — the YAML file must be inside the opened folder.

#The robot is lying on its side

The model uses a different up axis. Change Up axis in settings.

#I can't open a folder (browser)

Open folder is greyed out in Firefox and Safari. Use Pick files.
Your browser shows a permission prompt the first time, and again each session. If you dismissed it, click Open folder again.
Opening a folder needs a secure page. Use https://urdf.deyuf.org, not a copy saved to disk.

#Pick files is slow

Pick files reads every file in the folder up front. Choose the smallest folder that still contains all needed packages, or use a Chromium-based browser and Open folder, which reads files only when they are needed.

#I can't see the reachability cloud

Make sure the Tip link is a link the arm moves, such as the tool point or hand. If the status says the link does not move with any joint, every sample landed on the same spot; pick a link further along the arm. The map appears around the robot after Sample; Clear removes it. If you moved Hide below up, set it back to 0% to see every cube.

#Saved poses or bookmarks disappeared (browser)

They are stored in your browser for this site. Private windows, clearing browsing data, or a different browser or computer start empty. Export a pose as JSON to keep it elsewhere.

#Joint sliders don't move a joint

Mimic joints have no slider; move the joint they follow.
A joint whose lower and upper limits are equal can't move. Check its <limit>, or tick Ignore limits to explore.

#Is my model uploaded anywhere?

No. In the browser, files are read and processed on your computer; the site only serves the app itself. In VS Code, everything runs locally.

#Still stuck?

Open an issue on GitHub with the message you see. If you can share the model, attach it — or a cut-down version that shows the problem.