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.
In SAP NetWeaver Administrator, choose .
In the Module List section, select the com.sap.portal.ivs.httpservice application.
In Web Module Details , in the Components tab, select the proxy service.
In the Portal Service Details area, select the HTTP - Bypass Proxy Servers property, and enter the relevant server information. For example, *.yourCompany .
Separate entries with a pipe character ( | ).
Restart the proxy service: