Error while updating the Document in Picture Library

hi,

I am getting an Error when i am trying to update a document in Picture Library and also i am not able to delete or upload a new document.

below is the error 

<nativehr>0x81020030</nativehr><nativestack></nativestack>The URL 'PicLib/finalcopy.jpg' is invalid. It may refer to a nonexistent file or folder, or refer to a valid file or folder that is not in the current Web.

Thanks

sal