"Blocked plug-in" error in Safari when opening a PDF file
Published on in Safari
Try to add object-src 'self'; to the Content Security Policy.
Then your users don't have to download the file to view it.
Table of contents
The problem
I was investigating an issue where Safari failed to display a PDF file. It instead just showed the text "Blocked plug-in."
The problem occurred only in desktop Safari.
The fix
The user could download the file to view it, but that would be cumbersome.
I did some quick googling but didn't find any good results.
Then I noticed that Safari's console showed an error message related to Content Security Policy (CSP).
In the end, the fix was to add object-src 'self'; to the CSP.
Interesting that other browsers don't require that setting.