Resolving "Unable to communicate with license manager" Errors

Summary: Tips for resolving the dreaded “Unable to communicate with license manager” error.

Updated: March 25, 2010 from Kelvin Cheng, McNeel Asia

From my experience, the solution is always…

1. Uninstall Rhino.
2. Delete the “License Manager” folder under C:\Program Files\Common Files\McNeel Shared\ (For a 32-bit) or C:\Program Files (x86)\Common Files\McNeel Shared\ (For a 64-bit)
3. Install Rhino 4 again and upgrade.

Updated: Jan 12, 2010 from John Brock, McNeel Seattle

A new reason has been determined that can also cause this error when running Rhino V4 under Vista or Windows 7. It has to do with a conflict with User Account Control. Right-mouse click on the Rhino V4 icon, and select Run as Administrator. If this solves the problem, then be sure to download and install Rhino V4 Service Release 7. Installing SR7 should fix the problem.

Updated: May 21, 2008

When you run either Rhino 3.0 or Rhino 4.0, you receive the following error message:

The “Unable to communicate with license manager” message is caused by Rhino's inability to communicate with its license manager module listed below. This error can occur in either Standalone and Workgroup Node installations.

This error is due to one of the following situations:

1. Missing license manager files.
2. Missing Windows System Registry entries.
3. Missing runtime library support files.
4. An errant license manager is running.
5. Windows Registry security issue.

To get to the current service release .

A new reason has been determined that can also cause this error when running Rhino V4 under Vista or Windows 7. It has to do with a conflict with User Account Control. Right-mouse click on the Rhino V4 icon, and select Run as Administrator. If this solves the problem, then be sure to download and install Rhino V4 Service Release 7. Installing SR7 should fix the problem.

On English-language versions of Rhino, the license managment modules are located in the following folder:

 C:\Program Files\Common Files\McNeel Shared\License Manager

Rhino 3.0 and Rhino 4.0 use different license management modules:

• The Rhino 3.0 license manager is named McNeelLM.exe.
• The Rhino 4.0 license manager is named RhinoLM.exe.

If the license manager module for the version of Rhino that you are using does not exist, then you will need to re-install Rhino from your CD.

If the license manager module for the version of Rhino that you are using is present, then the module might not be registered - there might not be information in the Windows Registry that allows Rhino to locate this module. To solve this issue:

1. Make sure you are logged into your workstation as the Administrator or an equivalent user.
2. Make sure to disable virus detectors and anti-spyware agents.
3. Using Explorer, navigate to the above mentioned folder. (C:\Program Files\Common Files\McNeel Shared\License Manager)

If the error occurs when trying to run Rhino 3.0, then:

1. Download and unzip this batch file in the same folder as McNeelLM.exe.
2. Double-click on the Register_McNeelLM.bat batch file.
3. Windows Vista users: right-click on the file and select “Run as administrator”.

The batch file will echo the results to the command line, thus verifying success or failure. To confirm this method resolved the problem, run Rhino 3.0.

If the error occurs when trying to run Rhino 4.0, then:

1. Download and unzip this batch file in the same folder as RhinoLM.exe.
2. Double-click on the Register_RhinoLM.bat batch file.
3. Windows Vista users: right-click on the file and select “Run as administrator”.

The batch file will echo the results to the command line, thus verifying success or failure. To confirm this method resolved the problem, run Rhino.

If running the above batch file returns an error, then download and install the latest Microsoft runtime libraries and try again.

Please restart the machine. The steps above may have been successful, but an errant license manager running in Windows can cause continued problems. Does Rhino run after the restart?

If the license manager module for the version of Rhino that you are using is present and the module us registered - you might not have enough rights to read the Windows Registry.

Run Regedit.exe.

Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to re-install Windows to correct them. Robert McNeel & Associates and Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk. For assistance, please contact McNeel Support

When open, find the RhinoLicenseManager.RhinoLicense key in HKEY_CLASSES_ROOT. For example:

1. Browse to HKEY_LOCAL_MACHINE\Software\Classes
2. Right-click the Classes key, then click Permissions
3. On the Security tab, under Group or User Names you should see at least four permission entries. Sometimes the “Unable to communicate with license manager” problem is caused by having no permissions on the Classes registry key.

If and ONLY IF permissions are missing, add them:

1. Click the Add button.
2. Type Creator Owner then click OK.
3. Select Creator Owner, then clear all the checkboxes in the Allow column under Permission for Creator Owner section:
4. 
5. Click the Add button.
6. Type SYSTEM then click OK.
7. Select SYSTEM, then select the Full Control checkbox in the Allow column under Permission for SYSTEM:
8. 
9. Click the Add button.
10. Type Administrators then click OK.
11. Select Administrators, then select the Full Control checkbox in the Allow column under Permission for Administrators:
12. 
13. Type Users then click OK.
14. Select Users, then select the Read checkbox in the Allow column under Permission for Users:
15. 
16. Click the Advanced button.
17. In the Advanced Security Settings for Classes dialog box, select the Replace all child object permissions with inheritable permissions from this object.
18. In the Advanced Security Settings for Classes dialog box, select the Include inheritable permissions from this objects' parent. checkbox.
19. 
20. Click OK - it may take several minutes to complete this operation.
21. In the Permissions for Classes dialog box, click OK

If the previous steps fail to work, you may need to run RegEdit as the System account using psexec. Download psexec, then run psexec -i -d -s c:\windows\regedit.exe

You should now be able to run Rhino and communicate with the license manager.