When attempting to perform a patch deployment, you receive the following error message under Progress Details:
 

Failed: Access Denied

Follow the steps suggested in this article:
https://www.gfi.com/support/products/gfi-languard/Remediation-Job-Status-stuck-at-Pending

Either the account used by the GFI LanGuard XX Attendant Service does not have rights to the computers, or there is a domain policy which limits the rights of the user LANGUARD_XX_USER. The software deployment starts under the local user LANGUARD_XX_USER, after starting, the process has one thread on which the deployment will be done. On that thread GFI LanGuard tries to impersonate the user of the GFI LanGuard Attendant Service. At this step, there are group policies which do not allow that local users to perform impersonation.