How to make sub report work in webApp.ear in adempiere

Hi. it’s looks like there is a trouble when we are using sub report in adempiere if deploy in webApp.ear. here is the clue : 1. in the main report report, right click subreport then choose properties 2. choose “subreport” tab , i choose “Use connection Expression” 3. choose “subreport (others)” tab 3.1. choose java.lang.string [...]