Checking the nonProxyHost Settings for the Theme Editor 
If the theme editor's preview function does not work correctly, you need to check that the portal is configured with the correct nonProxyHost settings.
Go to .
In the Portal Catalog, open .
Right-click proxy, and select Configure.
In the HTTP - Bypass Proxy Servers property, enter the relevant server information. For example, *.yourCompany.
Note
Separate entries with a pipe character ( | ).
Restart the proxy service:
Go to .
In the "Portal Anywhere" Admin Tools section, select Application Console.
Select the com.sap.portal.ivs.httpservice service and click show.
In the com.sapportals.portal.ivs.proxy.ProxyServerService row, click restart.
To check that your settings are correct, run the Server Side URL Connection Test. If the nonProxyHost settings are incorrect, the test displays an HTTP error. For more information, see Performing Theme Integrity Tests.