Problem importing PDFs and web pages to binder

I have been using Scrivener for years and never had any problem importing/adding pdfs or web pages into binders, but today this has suddenly become impossible

Ordinarily I would simple right click on the Add button and choose Web Page or Existing File options to do this - now the Web Page option is grey, so unavailable to me, and when I click existing file to try and import a pdf, all the pdfs in my files are also grey and unavailable. Only word documents appear to be available for import.

Anyone have any idea why this might have happened and how I can fix it?

I am using:
Macbook Pro 2010
Mac OSX El Capitan 10.11.4


Sounds like your focus is in the Manuscript folder. PDFs and web pages can only be imported into the research folder.