All PDF documents suddenly displayed as HTML document

[dr_heikef62050454]

Yesterday I purchased an eBook in PDF format. When I tried to download it, it didn't work, it was saved as Chrome HTML document. This morning I discovered that all PDF documents are now stored in HTML format. I am not sure, where to start fixing the problem or what caused the problem.

This is a screenshot, where I selected all pdf files. File names are correct, but shown as HTML.

What can I do?

[Test Screen Name · Accepted solution]

I don't see anything saying they are HTML documents. Yes, the Chrome icon, but that's all.