InDesign Exporting PDFs as Illustrator Files Instead

I had this issue the other day (aug 2020!!) and was searching for answers. This advice worked, to uninstall both Indesign and Illustrator then reinstall Indesign. My previously saved PDF files automatically converted from file type-Illustrator back to file type-PDF document. I wish to reinstall Illustrator again but I don't how that will work out... 

I tried Sjaani answer and it didnt work for me.

But I did discover that if you right click on the folder and select "Get Info" right at the bottom there is the OPEN WITH option and it is set on Illustrator. so just change it to PREVIEW and it should work normally.

I believe you're making yourself clear. I just believe you're wrapping yourself around the axle with a quirk of your individual system, and that when it comes down to it, you're doing better than you think.

1) File associations are not created and acted on by Adobe applications. They're created and acted upon by your operating system. And MacOS can occasionally be quirky about that, as Sjaani has also detailed to you.

2) Your own observations aren't lying to you – you're creating a real, normal PDF file and when your clients are receiving them, they operate as real, normal PDF files. But they're not magically transforming themselves from Adobe Illustrator files into real, normal PDFs through the email process. That Icon doesn't so much indicate that it is an Adobe Illustrator file as it indicates that right now PDF files are associated with Adobe Illustrator on your system.

Yes, the way your system is set the PDFs you're creating with InDesign are opening in Adobe Illustrator. And that's not the best thing, because Illustrator can occasionally scramble PDF elements and settings when you open them in Illustrator.

So don't do that.

Right now you have a clunky workaround to prevent that. Just Control/right click on the file and open it in Preview (Apple's default) or Acrobat. Generally, you can fix that as easily as changing the file association as I outlined above. If that doesn't work, as Sjaani outlined above, just uninstall Illustrator and Acrobat on your system, then re-install Acrobat first and then reset the file association from Preview (default) to Acrobat (default). Once that's done, then re-install Adobe Illustrator.

It stinks that you may have to do this, which in the worst-case scenario above will take between a half hour and an hour for you to do. But it will fix your problem.

In the meantime, don't panic about creating your multiple job-related PDF files early this week. Again, you're creating real, normal PDF files.

@Bradford – The automatic default to Preview isn't surprising. Apple's PDF utility, by default, is used to open PDFs. And frequently, when the MacOS or utilities get updated, Preview will again set itself to supersede Acrobat. Once you universally (re)set the default app to Acrobat, all will return to Acrobat PDFs ... 'til the next time.

Glad things have worked out well for you.

Randy

When you create the file, then control/right click on it in Finder, what default application does it show under the Open With menu command? Does it show Adobe Acrobat among any of the options?

If the default application is different and Acrobat is among your options, just:

1) Right-click on the file again in Finder and select the Get Info command.

2) Go to the Open with: section and change the options box to reflect Adobe Acrobat, then click the Change All ... button and confirm your choice.

End of problem.