Sorry I thought that I have sent all files, sending them now

In reality, if we send more than one attachment, he only gets the first one

I have created a report that contains a master-detail relation and this work fine when there is data, but, when I have no data in the master dataSource an error 'Column does not exist in Data Source and relation can't be created!' is raised and none of the reports are printed. I Would like to know i...