====== Diagnosing Rhino Startup Errors ======

>If Rhino fails to start or crashes while starting on your computer, here are some things you can do to understand what is happening on your computer and fix the problem.

====Rhino 6 (and later)====

>The same process works for Rhino 7 and 8 -- just replace "6.0" with "7.0" or "8.0" in the registry key.

  - Open the Registry Editor (From the Start menu in Windows, type **regedit**, then press Enter).
  - In the registry, under HKEY_CURRENT_USER\Software\McNeel\Rhinoceros\6.0\Global Options\Debug Logging
  - Create REG_DWORD (32) value named **Enabled** (if it doesn't already exist)
  - Set **Enabled** to **1**
  - Create REG_DWORD (32) value named **SaveToFile**  (if it doesn't already exist)
  - Set **SaveToFile** to **1**
  - Start **Rhino** using the **shortcut**, not by clicking on a data file.
  - Send the **RhinoDebugMessages.txt** in your Documents folder to **tech@mcneel.com**.

--> Rhino 5^

--> Rhino won't start when double-clicking or dragging and dropping a file
  * Double-click a Rhino **shortcut** on your desktop, or click a Rhino item in your **Start** menu.
  * If Rhino starts:
    * Open the file from the **File** menu > **Open** or the **Open** toolbar button. If the file won't open, the problem is probably with the file. Try the **Audit3dmFile** command on the file.

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--> Rhino won't start from a desktop or Start menu shortcut
  * Start in SafeMode.
    * SafeMode starts Rhino without using accelerated graphics and without loading plug-ins.
    * On the **Windows Start Menu**, click the item **Rhinoceros 5.0 in Safe Mode** or **Rhinoceros 5.0 (64-bit) in Safe Mode**.
      * Answer **Yes** to loading Toolbars and **No** to loading RDK.

  * If Rhino starts in SafeMode, there is likely a problem with a video driver or a plug-in.
    * In the Rhino menu: //Tools - Options - View - OpenGL//, uncheck the box at the top labeled **Use accelerated hardware modes**. 
    * Close Rhino and start normally (not using SafeMode). 

    * If Rhino starts with accelerated hardware disabled, the problem is likely your video card driver. 
      * Download and install a current driver for your video card. It's best to get your driver update from your hardware manufacturer and not from a third-party site.
        * NVIDIA:  http://www.nvidia.com/Download/index.aspx
        * Intel:   http://downloadcenter.intel.com/Default.aspx
        * ATI/AMD: http://support.amd.com/us/gpudownload/Pages/index.aspx
        * Apple:   http://support.apple.com/downloads/#bootcamp
        * Other sites appropriate to your video hardware.
        * Note: If you're on a laptop, you'll probably have to get your driver update from the laptop maker.
      * Restart Rhino normally (not using SafeMode).

    * If Rhino still crashes after disabling hardware acceleration, the problem may be a plug-in.
      * Restart in SafeMode, and check the box **Use accelerated hardware modes**. 
      * In the Rhino menu //Tools - Options - Plug-ins//, uncheck the **Enabled** box for all of the plug-ins that did not ship with Rhino, and check the box **Ask to load disabled plug-ins** at the bottom.
      * Close Rhino and start normally (not using SafeMode). 
        * Answer **No** to loading all of the plug-ins you disabled.

      * If Rhino starts with some plug-ins disabled, the problem is one of the disabled plug-ins. 
        * Restart Rhino normally and answer **Yes** to loading **one plug-in at a time** and **No** to the rest until you determine which one causes the problem.
        * When you have determined which plug-in causes a problem, go back to //Tools - Options - Plug-ins// and check the **Enabled** box for all of the plug-ins that don't cause a problem.

      * If Rhino crashes in SafeMode or you can't resolve the problem with these methods, contact us at http://www.rhino3d.com/support for help.

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