Checking the Proxy Settings for TREX 
If a portal with Knowledge Management and Collaboration (KMC) is unable to communicate with TREX, it may be due to the portal trying to access TREX using a proxy server. If this is the case, you have to change the configuration so that access does not take place using the proxy server.
You have the NWA_SUPERADMIN UME role assigned to your user.
Open SAP NetWeaver Administrator and choose .
On the Overview tab page, filter for com.sap.portal.ivs.httpservice.
The system displays the com.sap.portal.ivs.httpservice Web module details.
In the Web Module Details screen area, choose .
The system displays the property settings of the proxy portal service in the Portal Service Details screen area.
In the Portal Services Details screen area, check if a proxy server is configured.
If a proxy server is configured, enter the TREX host in the Value field for the HTTP — Bypass Proxy Servers parameter.