Global Protect Error : 'PanGPS.exe - System Error' and missing 'wlanapi.dll' from the computer

This article discusses the issue of failure of installation of the GlobalProtect agent with the following error:

What are the symptoms of this issue ?

This issue can be seen while installing the GlobalProtect agent and an error would be present stating that the installation did not complete correctly.
Any connection attempt to the portal from the GlobalProtect agent would fail with status as 'disconnected'
Accessing the portal from the browser works fine with the authentication page being presented.

How to fix this issue

-- 'wlanapi.dll' is related to 'Wireless LAN Service' in windows.
-- Check and install this service if it is not installed on the computer.

Below are the detailed steps:

a. Go to Server Manager.
b. Click Manage in the upper right corner.
c. Click Add Roles and Features.
d. Click Next > Next > Next.
e. At Server Selection select the 'server'
f. Click Next > Next.
g. At Features check Wireless LAN Services.
h. Click Next > Install.
i. Restart your server.

Now uninstall  the present versions of the GP Agent(s) from the computer and install it again.

NOTE: This is not an issue with the Global Protect Agent package, but with the Windows missing the 'wlanapi.dll' file which is required for functioning of Global Protect 'PanGPS' service.

Following is an example from Windows Server 2012R2:

1. Open the 'Server Manager' 

2. Install the 'Wireless LAN Service'