New user combining/merging pdfs created in adobe

 I've tried several times and must be leaving out a step....

I add each of two pdfs documents to the list and select them both 

and click "combine" - when the file window comes up it is empty and 

says  my file is already open. But no text. 

Can someone walk me through this process? 



did you try to do this with the PDFCreator or the PDFArchitect?

Does this happen with any PDFs you try to combine?