OK - here goes: I am a newbie - using moodle now for a few months; also new to linux. I want to make course resources easily accessible to my students - so what I have done is on the front page I have a "Page" resource that opens up a page on which I have listed resource files hyperlinked to the resources. Using Google Chrome browser this works fine - the pdf file opens in a new window. However using Chrome browser, a download window opens. For a workaround, I have a similar page on a "sister" site in Joomdle that reliably opens the pdf file to view. Is there a setting to get the popup to display a pdf file instead of a download window (without going to joomdle)?
Check your display options - you can set it to open in popup. That should fix it. I am presuming that you used the same browser on the Joomdle site and that it isn't a browser setting?