acrobat dc

It looks like you've posted this question twice - once in the Reader forum and apparently in a non-product forum. There is no need to double-post. Please provide all information requested in your other question: Adobe Acrobat

Based on what you describe, it sounds like you are using the free Adobe Reader, which cannot edit PDF files, even if you have a subscription to e.g. the PDF Pack or Export PDF. You can perform certain edit operations (e.g. merging files into one PDF) by using the online service, but that would not work from within Reader. If you do have both Reader and Acrobat installed on the same computer, you will need to make sure that you launch the correct application if you want to edit PDF files: Make sure that you are actually using Acrobat and not Reader.