You cannot share applications as a host, or cannot view shared applications as a participant in a meeting. Rather you see the error "Security check failed." Two reasons arise for this error, both stemming from the DLLList821.dll. This DLL installs when you install the meeting plugin. The meeting plugin may be out of date and must be replaced. Uninstall
the meeting plugin and delete the WDPlugin directory. You will find this directory by
1. clicking Start and entering %appdata% in the command window
2. navigating to C:\[user profile]\AppData\LocalLow\WDPlugin
Reinstall the plugin and try the meeting again. Should this fail then the greater probability is that your workstation or the environment that hosts your workstation for meetings, Citrix, etc., does not have the current code signing certificates that allow the plugin to run. Check this by
1. Opening the WDPlugin folder
2. Right click DLLList821.dll and click Properties,
3. Click the Digital Signatures tab, highlight International Business Machines, and click Details
4. Click the General tab in the popup window and then click View Certificate.
5. Click Certification Path in the popup window.
This displays a chain of trust for the code used to run sharing. If any of the certificate icons has a red x then the your system does not have that certificate or does not trust it. Resolve this issue by going to the Verisign site to retrieve the certificates and install them into your system using Internet Explorer.
1. Open Internet Explorer, click the Tools menu and Internet Options.
2. Click the Content tab and Certificates.
3. Use the Trusted Root Certification Authorities tab for the root or Intermediate Certification Authorities tab as needed and Import the certificates.
At least two issues found resolution by importing Verisign Class 3 Public Primary Certification Authority G5 and the intermediate Verisign Class 3 Code Signing 2010 CA.
Afterwards test your meeting to ensure proper working of sharing.