AppXtender Document Manager error "Invalid Logon Handle"
This message is common in a scenario where the local client machine running Document Manager cannot contact the license server to obtain a license. If you are getting this error after the machine had been working for a period of time then suddenly stopped working, this can be due to having previously loaded an .axs settings file which had a cached connection. The lscache parameter in the .axs settings file only holds the license connection informaton for 2 weeks. If the system can't get to the license server to verify valid licensing, after that two weeks it will fail to contact the license server and to log you in. Regenerating the settings file and reloading it "refreshes" the cached connection.
To fix permanently, you'll need to make sure port 9251 is open between the server and the client machine so that contact with the license server can be established.