I have a similar problem, if anyone could help,
OJS 2.4.8.1
I used to upload xml files in galley and pdf files as a supplementary file,
And the user interface will show a pdf button where it opens in a new window and shows the pdf in the reader,
Now it doesn’t read but can be downloaded, and shows this box,
If i click on download, it downloads the pdf normally, but it used to open the pdf in the reader itself,
The only recent thing that happened in the past few months, was that we switched servers, but other than that nothing else was changed in the configurations or anything.
I checked the database and everything, all are the same for the past few months, nothing have changed, to my knowledge.
I have both google pdf viewer active, and PDF.JS PDF Viewer Plugin enabled in the plugins,
Could you please help?