Troubleshooting

The Studio

The sidebar shows “Service unavailable”.: The Studio cannot reach the simulation service. Check that Deneb Aero is running: the icon in the menu bar (macOS) or by the clock (Windows), or docker ps on Linux. The Studio retries by itself. If the service does not start, open its logs (macOS: Show logs in the menu; Linux: docker logs deneb-aero).
The Projects page says “This computer’s simulation workspace is connected to another account.”: The computer is connected to another Deneb account. Sign in with that account. See Connecting This Computer.
A banner says that changes could not be saved.: The project records could not be saved to your account, usually because the connection was lost. Select Retry saving. If it keeps failing, use Recover changes to download the unsaved changes before choosing Use saved versions.
A draft says “This draft is no longer available on this device.”: The CAD file of a draft is kept in the browser where the draft was started. Open the draft in that browser, or start a new analysis.
The Studio on aero.deneb-systems.com cannot start runs.: This is expected. Runs and flights happen in the Studio of the application (http://127.0.0.1:43127/?studio). See How Deneb Aero Works.
The Flow tab is empty or does not draw.: The flow views need WebGPU. Use a current version of Chrome or Edge. A greyed run chip means that run’s flow was not kept (Disk Space).

The wind arrow points the wrong way.: Change Wind blows along in the Geometry step. The arrow must point from the nose to the tail.
A control surface cannot be assigned.: The surface is not a separate solid in the CAD model. Export the model with each control surface as its own solid, with a hinge gap. See Preparing the Geometry.
The Review step shows that the mesh does not fit in memory.: The largest mesh needs more memory than a run may use on this computer. Close other programs, use a computer with more memory, or, on Windows, let WSL use more memory (re-run the installer or edit .wslconfig).

A run did not finish.: The Runs tab shows the stage where it stopped and the message. Select Try again to resume it from its checkpoint. If it fails again at the meshing stage, check the geometry notes of the Geometry step.
A run is “Not settled”.: The iteration limit came before the loads settled. The values are shown but should be treated with care. This is common past the lift peak; see the Unsteady past the stall block.
Runs stopped when I quit or updated Deneb Aero.: They are kept as interrupted and resume from their last checkpoint when you select Resume.
The disk is full.: Free the flow of runs you do not need to view (Disk Space).

The aircraft switched to RTL by itself.: The cockpit tab was hidden, so pilot input stopped and the radio failsafe triggered. Keep the cockpit visible while flying.
“Disconnected — Another client is connected”.: Another browser tab is connected to the flight. Close it, or select Back, End flight and fly again.
The simulator is not available on macOS.: On macOS 14 and 15 the simulator needs Docker Desktop. Install and start it. On macOS 26 it runs without Docker Desktop.
The simulation speed is below 1.0×.: The computer cannot run the simulation in real time, often because a CFD run is using the cores. The flight is still correct, only slower.

See the table of installer errors in Installing on Windows.

Write to contact@deneb-systems.com. Give your account ID (Account ‣ Profile), the version (Account ‣ This computer), what you did and what you saw.