The SolidWorks Flow Simulation can give you a message stating that authorization has failed. This is because on the client machine  the License Manager was opened and the License Order tab was selected. This changes a registry setting that needs to be corrected. Below is the work around for this and it has been corrected in 2010 SP3 which should be released in the middle of April.

Here is the workaround – please be sure you are comfortable editing the registry prior to attempting this procedure. Consider making a backup of the registry beforehand, in case you make a mistake.

1. Close SolidWorks.

2. Close SNL on the client machine (if you have the SNL window open).

3. Open the Registry Editor by going to Start Menu -> Run and type “regedit” (without the quotes). (For Windows 7, just type regedit in the “Search programs and files” text box in the Start Menu).

4. Browse to the following location: HKEY_CURRENT_USER\Software\SolidWorks\Licenses\Settings

5. You will see a string value called “License Order” with a series of comma separated numerical values – double click the string to edit it.

6. Among the various numbers, you should see 27. Replace the 27 with a 28 and click OK.

7. Close the Registry Editor.

8. Open SolidWorks and enable Flow Simulation – it should now work as long as SNL is configured correctly and at least one free license of Flow is showing in the License Usage tab of SNL.

Please note that after this procedure, if you click the License Order tab of SNL on the affected machine (even without changing anything) it will reset the 28 back to a 27, causing the issue to resurface. This means that you will need to go through the above steps again.