After installing Adobe Acrobat, can I revert to Preview for handling PDF from Firefox?

I was used to download PDF from Firefox and open them with Preview PDF.

Yesterday I installed Adobe Reader and now each time I click on a PDF link Firefox tries to open the PDF with Abode Reader. And it doesn't work even. See the picture below.

How can I go back to the previous behavior?

1st thing to try

1. Open Firefox
2. Open Preferences (Firefox > Preferences, or Command + ,)
3. Select the Applications tab
4. Search for "pdf"
5. Change action to something else, then change it back to "Always Ask"

Verify this is set correctly

1. Open Finder
2. Search for .pdf
3. Right (Option) Click the first PDF that appears.
4. Click Get Info
5. Expand Open With (if it isn't already)
6. Change it to "Preview"
7. Click Change All button below the drop down menu
8. Accept the prompt.

For a visual representation: