Hi Sandip, usually when I've received an error such as that it's because the partial refresh can't locate the element or area it's trying to refresh. Is there a visibility or rendering setting that might be tripping you up? What I did to get around those errors was surround the troublesome element/field/section in a panel or <div> that's always visible then have my partial refresh operate on the surrounding panel or <div>.
Hope that helps,
Judy.