RVE>Zip file>Edit> Save clicked ' 502 Proxy Error ' is shown.

RVE >Zip file >Content> Click Edit link.
Select check box for 'Set a New Start File:'.
The Zip file content will be shown in the Tree view.
Click any link in that tree view.

Edit the custom caption and click Save.

The page shows loading and after sometime, the follwoing Error page is dipalyed.

Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /xwiki/bin/view/CurrikiCode/AssetSaveService.

Reason: Error reading from remote server

Thrice I tried and I got this issue.

http://next.dev.curriki.org/xwiki/bin/view/Coll_ashpee/Zipfile?viewer=assetedit&bc=;Coll_ashpee.12FebCollection%2Dpublic