The following error is displayed after logging on to NetScaler Gateway:
"403 - Forbidden: Access is denied." 

The following are some points to verify in the NetScaler Gateway configuration for StoreFront or Web Interface when receiving a 403 error after authentication at NetScaler Gateway:

1. Ensure to link the intermediate and root certificates in NetScaler console under Traffic Management > SSL.

2. Verify all NetScaler Gateway session policies Edit Action to confirm if the Store URL and Name is spelled correctly.

3. Ensure that the StoreFront address in the NetScaler Gateway Session Profile matches the site address in StoreFront.

4. Ensure that the call back address is set to HTTPS.

5. Ensure that there is a DNS Host entry on StoreFront to point to NetScaler Gateway virtual server.

6. If the Root CA is internal CA certificate then ensure that the Root CA certificate are added on both StoreFront as well as on NetScaler, so that they trust each other.

CTX139319 - How to Configure NetScaler Gateway with StoreFront and App Controller