For any Outlook 365 users ending up on this page looking for a solution:

Go to Outlook > Acrobat tab > "Change Conversion Settings" then UNCHECK "Output Adobe PDF Portfolio when creating a new file" and click OK. Problem solved.

(Really this "Portfolio" option should only kick in when saving *multiple* emails to PDF, there is literally no use case for saving a single file to a PDF Portfolio instead of a straight PDF...)

Wow. Adobe literally told you to go f@&k yourself. WMrRaj must really hate you.

In my version of Acrobat Pro DC I needed to go to File>Create>Combine files into Single PDF>Option (gear icon)>uncheck the Save as PDF Portfolio box

Worked for me. Acrobat Pro DC. Thank you.

This process worked for me on 29/08/22. Thank you.

Thanks

I can confirm that as of today, 17 AUG 2021, the answers here are invalid for Acrobat DC. For example, the Acrobat options in Office 365 - desktop or cloud, do not have any portfolio management options. The options to stop portfolio creation from a group of emails does not exist. Checking one or both boxes makes no difference.

Make sure you aren't using the short cut or you'll spend time pulling your hair out.

I found the solution! Open your PDF document and convert it to a word document. Save it as a word document. This allows for the digital signatures to stay intact. Once converted to a word document resave it as a PDF document then you can merge or combine your documents without losing digital signatures or having to convert it to a portfolio document. It's a bit of a pain but it works.

Do not like the portfolio feature!! I have to keep that feature on in order to keep electronic signatures in my document if I want to combine it with another document. However, the program I use to obtain those signatures doesn't recognize the portfolio and simply puts the Adobe logo in as my attachment. It's incredibly frustrating!!

Thank you! I switched jobs a few months ago and have a new laptop and couldn't figure out why it was creating a Portfolio when I selected combine files!

@JustMe - that totally worked. Thank you!

open adobe
click tools
click the combine files icon
click options at top of page
uncheck "save a PDF portfolio
done

this solution does not work, adobe continues to force the portfolio direction or it just continually duplicates pdfs I am trying to combine. idk what freakin genius decided this addition to adobe was great but they should be kicked repeatedly.

It still works N A you need to go tools > combine files (click on open) > then up the top there will be an Options (gear icon) > once u open this you need to make sure hat both save a as pdf Portfolio & convert all files to pdf Portfolio are off (if the second one is click you need to click the first one to unclik the second one then unclick the first option again)

If your saving from a email in outlook or something you need to go to the change conversion settings in the outlook program

This answer is from 2 years ago and does not work for me. I am using Adobe Acrobat Pro DC and I cannot find "Combine App" or the "Options". PLEASE HELP ... I CAN'T STAND THIS PORTFOLIO ****!! ........................THANK YOU!!