What to do when you receive a WSUS Connection Error?

Step 1: Ensure Hardware and Software Specifications are met

• Make sure WSUS specs follow our guidelines (we strongly recommend Windows 2016).

Step 2: Ensure the patch classifications include only the relevant patches for the environment

• Relevant languages
  • To locate relevant languages, go to:
    1. Options
    2. Update Files and Languages
    3. Update Languages
  • Ensure updates are only in the languages used (recommended English). If there are more. please remove language packs from classifications and products to synchronize. Go to:
    1. Options
    2. Products and Classifications
    3. Products (uncheck non-relevant language packs) 

Step 3: Ensure IIS WSUS Application Pool Settings have been modified

• To located IIS WSUS Application Pool Settings, go to:
  1. Launch Server Manager
  2. Launch IIS Manager
  3. IIS Console
  4. Click on Application Pools
  5. Right-click ‘WsusPool’ and select ‘Advanced Settings’ 
     • General - Verify the value of 'Queue Length’ under the General section to 30,000
     • Rapid-Fail Protection
       • Verify 'Service Unavailable' Response Type from default HTTPlevel to TcpLevel
       • Verify failure interval minutes from 5 to 30 minutes
     • Recycling
       • Verify the value of ‘Private Memory Limit’ under the Recycling section to 0
• If changes were made, open an administrative command prompt, and run IISRESET

Step 4: Ensure the following settings are configured properly

• Verify that the WSUS content folder has been configured with suitable permission
  • Note: Network service and WSUS Administrators should have full control on this folder
• Verify that IPv6 has been disabled