If Rhino 4.0 fails to start on your computer, use the Rhino Debugging Harness to generate detailed information that will help the Rhino Development Team understand what is happening on your computer.

1. Install the latest build of Rhino 4.0 (Service Releases are downloadable from www.rhino3d.com/download.htm).

2. Download the Rhino Debugging Harness and save it to your desktop.

3. Start RhinoDebugHarness.exe.

4. Select the Start in Safe Mode checkbox.

5. Clear the OpenGL Acceleration Enabled checkbox.

6. Click the Start Rhino Button.

Let Rhino try to start for a few moments.

Did Rhino start properly?

Yes: Keep Rhino Debug Harness running, and proceed to Debug Phase 2.

No: No further testing will help diagnose this problem. Please do the following:

• Click the View Log button.
• Email a copy of this startup log to McNeel Tech Support at tech@mcneel.com.
• Please let McNeel Tech Support (tech@mcneel.com) know that Rhino does not start in Safe Mode.

1. Clear the Start in Safe Mode checkbox.

2. Clear the OpenGL Acceleration Enabled checkbox.

3. Click the Start Rhino Button.

Did Rhino start properly?

Yes: Keep Rhino Debug Harness running, and proceed to Debug Phase 3.

No: Please let McNeel Tech Support know that:

• Rhino starts in Safe Mode
• Rhino does not start with OpenGL Acceleration Disabled.

1. Clear the Start in Safe Mode checkbox.

2. Select the OpenGL Acceleration Enabled checkbox.

3. Click the Start Rhino Button.

Did Rhino start properly?

Yes: Rhino seems to be functioning properly. Close the Rhino Debug Harness.

No: The problem is likely related to your OpenGL card or driver. Please download the latest OpenGL driver from your computer or video card manufacturer. If this does not solve the problem, please contat McNeel Tech support and let them know that:

• Rhino started in Safe Mode.
• Rhino started with OpenGL Acceleration Disable.
• You updated your video driver.
• Rhino does not start OpenGL Acceleration Enabled.