rem: var resource = GetResourceFromUri(uri); var msgfolder = resource.QueryInterface(Components.interfaces.nsIMsgFolder); return msgfolder; 
add: dump("GetMsgFolderFromUri of " + uri + "\n"); try { var resource = GetResourceFromUri(uri); var msgfolder = resource.QueryInterface(Components.interfaces.nsIMsgFolder); return msgfolder; } catch (ex) { dump("failed to get the folder resource\n"); } return null; 
context: function GetMsgFolderFromUri(uri){	var resource = GetResourceFromUri(uri);        var msgfolder = resource.QueryInterface(Components.interfaces.nsIMsgFolder);        return msgfolder;}
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