Symantec Intelligence Services is introduced in SGOS version 6.6.3.x. When enabling it, you may see that the Application List will is empty.

Management Console > Configuration > Application Classification > General > View Application/Operation List displays a blank page.

When trying to apply an Application Name under VPM it will prompt an error:

The ProxySG is unable to connect to Blue Coat.
Please ensure that you have;
- Installed a valid Blue Coat license and downloaded the database.
- Enabled Application Classification

Tried these few and it still failed;
- Moving between 6.6.3.2 <> 6.6.3.3
- Disabling and enabling Application Classification 

License validated;
Retrieve License Key 
MC > Maintenance > Licensing > Install > Retrieve 

Check License 
MC > Maintenance > Licensing > View > Refresh Data 
Look under Intelligence Service Bundles

Note: This procedure requires that you have a temprorary evaluation license for Blue Coat WebFiltering. Before you proceed, contact Blue Coat support to request it, and cite this article as the reason. 

1. Disable Application Classification: Browse to Configuration > Application Classification > General and remove the check next to Enable Blue Coat Application Classification on this device.  Click Apply
2. Change the data source to BCWF: Browse to Configuration > Content Filtering > Blue Coat > Data Source. Click the drop-down menu and select WebFilter rather than Intelligence Services.
3. Apply the evaluation WebFilter license:  Configuration > Content Filtering > Blue Coat. Enter the WebFilter username and password, click Apply, then Download Now. 
4. Click View Download Status to verify a successful license download. In some cases, users have reported that the download process results in a 401 Unauthorized error, yet the issue was still resolved with the next step.
5. Change the Data Source back to Intelligence Services and click Download Now.
6. Wait up to ten minutes to download the database.
7. Browse to Configuration > Content Filtering > Application Classification > General > Download and click Download Now. the database. 
8. Click the General tab at the top of the Application Classification page and click View Application List. The list displays.

Note: If this issue occurs in SGOS 6.7.4.x it may be related to bug SG-12947.