•Check the Extensions log within FreeFlyer. You can access the log through FreeFlyer's Help menu by selecting "View Extensions Log." It's possible that the Extension failed to register because you failed to follow the specified rules for defining your Extension's interface. You may have also used an object name which is reserved or already in use by another Extension. In any case, the relevant information will be presented to you in the Extensions log.
oIf the Extensions log fails to reference your Extension at all, it is not registered correctly.
•Check the Extensions Manager activity log within the Extensions SDK. The activity log contains information about the success or failure of the Extensions Manager as it attempts to register your extensions, and in the cause of a failure to register it will contain any relevant information. To show or hide this log choose Activity Log from the View menu in the file bar. Selecting this option will display the activity log as part of the Extensions Manager GUI.
•FreeFlyer Extensions can only be used with the FreeFlyer Mission tier.
•FreeFlyer can not be open when the Extension is built
•If you move the location of your Extension DLL file, you must re-register the Extension in that new location
•Because of Windows security architecture, the Extension must reside on the local machine in order to register successfully. Make sure you're not trying to register an extension residing on a remote machine.
•The Extensions Manager and Visual Studio must be run with an Administrator or Power User account
•You can not use an object name that is reserved or already in use
•The extension may have dependencies on other DLLs which cannot be located. Make sure any required dependencies either reside in the same directory as the Extension, or have been installed on the machine (in the case where a redistributable installer is available).
•Ensure that the Extension interface and class have public access modifiers
•Make sure that you added the Extensions Registration code
•Make sure that "Register for COM interop" is checked in the Build tab
•When selecting to register the extension as part of the build process, Visual Studio must be run with administrator privileges.