InDesign fails to open the PDF
The PDF file format is under-appreciated as a file format for saving lots of documents. It is great for saving high-quality artwork and documents. It can save layers for some design software so that the document can be edited later. There may be cases where InDesign may fail to open PDF and there are a few reasons why this happens.
1] The PDF file is protected by a password
One advantage of the PDF file format is the ability to protect the file using passwords. You can add a password to restrict access to opening the PDF document and you can also add a password that will restrict making changes to the PDF document. If you can open the PDF file, you may not be able to make edits to it without a password. You will notice that lots of organizations will send out official documents as PDFs. The PDF files are protected and, in some cases, if they want the document to be signed, the receiver will be sent a password. If you attempt to open a protected file in InDesign, it will ask for the password. If you are supposed to have access to the PDF file, you may then need to contact the sender to get the password.
2] The PDF file is very large
InDesign may have trouble opening a file if the file is very large. It may refuse to open, or it may process very slowly. In cases where you set your InDesign document import option to embed placed files instead of just linking to the files that contain them, the size of the file can make the process slow or in some cases stop. Embedding a file into InDesign forces InDesign to load all the files instead of pointing to the location of the original file. You may have created a document in Illustrator or Photoshop, and it is very large, this file could then cause InDesign to be unable to open the PDF if you embed it instead of linking it. in cases where the file is large, you may have to allow InDesign to open the file even though it may appear to have stopped.
3] The PDF file is damaged
A PDF document that refuses to be opened in InDesign may be somewhat damaged or incomplete. To check if the file is damaged, try opening it in another software that can open PDF. If the file is damaged, try to get the original or you may have to recreate the file. A lot of software can create or save as PDF; however, they may have problems when you try to use them in another software such as InDesign. When you create a PDF using other software, be sure that the PDF file is set for compatibility with other software. For example, Illustrator can create a variant of PDF, however, unless you tick the Create PDF Compatible File check box when you save it, the file will not work in InDesign. Read: The most common Photoshop File Formats that you can use.
