Could not access any GIS Server machines. Please contact your system administrator

Error Message

Accessing ArcGIS Server through ArcGIS Web Adaptor located in a perimeter network returns the following error:

Error:   
Could not access any GIS Server machines. Please contact your system administrator.

Cause

The following are possible causes for this issue:

• Insufficient hardware resources on the server hosting ArcGIS Server may cause a loss of connectivity.
• Windows Firewall rules do not allow access for ports 443 and 6443 on the ArcGIS Server machine.
• Certificate name mismatch - common name (domain name) in the certificate does not match the address in the address bar of the browser.
• ArcGIS Web Adaptor starts before ArcGIS Server, and is unable to establish a connection to the machine.

Solution or Workaround

The solutions provided are specific to each situation described above.

• To check the system requirements of ArcGIS Server, refer to ArcGIS Server system requirements overview.
• To open a port for Windows 7 Firewall, refer to Microsoft: Opening Ports in Windows Firewall. For Windows 10, refer to Microsoft: Create an Inbound Port Rule.
• Change to a self-signed certificate by referring to ArcGIS Help: Configure ArcGIS Server with a self-signed certificate.
• Restart ArcGIS Web Adaptor or rerun 'configurewebadaptor.sh'. To do so, refer to ArcGIS Help: Configuring ArcGIS Web Adaptor after installation.