Can you take a look in your DB: go to the table article_galleys and find the entry with galley_id = 132. Then see the file_id in that entry – I think it should be 202. Then go to the table article_files and then go to that file with the ID = 202, and see how the file_type is looking? – I believe the file type is not correct (e.g. application/pdf). If so check this one on MIME type detection more generally.
I’ve just upgraded from 18.104.22.168 to 3.0.2, and I’m having a similar problem. Every time I click on a PDF or full text link it downloads the file instead of showing the content. Tried to check the article_galleys table but it no longer exists. This can be seen here:
Hmmm… The mime type seems to be correct. The table is now called submission_galleys. Could you then double check the file_type there?
Also, is the pdfViewer generic plugin (Settings > Website > Plugins) enabled in your installation?