How to move .pdf file from Download to Doc Folder or another Folder

[MacKenrick]

I've been trying all day to figure out how to transfer a 4.5mb .pdf file from my Download folder to my Docs folder. I've even tried using ES File Explorer. I select the .pdf file and select ES Save to, then select my docs folder then I select "Select". I then get an error message that states: "This operation is not supported".

Is there any way of moving a .pdf file from my Download folder to my docs folder or My Documents folder (using ES File Explorer or any other method)?

I'm using a Moto X gen I. I can't believe it is this difficult to move a simple file from Downloads to another folder.

Thank you for your help.

 

[Sir Alex]

While in ES File Explorer, don't you get the following options when you press and hold on the file: copy, cut, move, etc..?