1. Open a new, empty PP project.
2. Go to Edit>Preferences>Media...
3. Take note of where the Media Cache files are stored on your hard drive.
4. Below that, Clean the Media Cache Database.
5. Close down PP. Use Explorer or Finder to navigate to the location you noted from step 3 and delete those files.
6. Restart PP and let the Cache rebuild itself.
Fantastic! my clips are back! I had about 20gb sitting there. The 3 titles red flagged are still missing however, but this is maybe due to the way I laid them there, modifying an instance of the first one, I don't know.
Thank you for that!
I've never seen a title go offline simply because it's stored in the project file itself. The only thing I can think of which could cause that to happen is if the project was created on an older version of PP where the titles were stored separately.