Not able to execute mail template preview for base object table as PWOHelperPWO for pre defined and custom mail templates

Hello All,

I am trying to execute my custom template which is based on PWOHelperPWO table.

So there are no records when i select the preview icon and message is like : Auxiliary table Request procedures.

Even i have checked for pre defined templates also but the same issue for the same base table.

Any suggestions please?