Viewer pane pdf Nitro

All of a sudden the viewer is not displaying .pdfs.

Windows 10, 32 bit.

I recently installed Nitro. But that was a week ago and viewing has been ok unitl today.

Some files ARE viewing, but not many.

Other odd behaviour - a pdf created from a Word document with a "DRAFT" watermark is just displaying some of the DRAFT letters eg, "DR" or "DRA", only - nothing else.

I have gone into Plugins in Viewer settings, and the Nitro PDF preview handler is ticked.

Any help appreciated.

Try reinstalling your PDF viewer.

Check it's working in File Explorer's viewer pane.

Please link your account if you're still having problems.


I tried to link my account yesterday, but it didn't seem to recognise my email - - but could downloaded my reg. number.

I uninstalled Nitro and reinstalled it. That hasn't made any difference. But I can't open anything in the File Explorer view pane - at first getting the message something wrong with Nitro preview handlers.

The reg number can be found within Opus via Help > Licence Manager. Email address isn't important.

The forum's account linking page has instructions and a video showing exactly what to do if you need them.

It looks like you've already linked your code to another older forum account (Hudson). We can unlink that account if you want to link the code to this one. Let us know if you want to do that.

Re Nitro, if its preview handler isn't working in Opus or Explorer after reinstalling it, it's something you may need to ask the Nitro developers about. But it's also worth checking which preview handler has PDF assigned to it, which you can do in Opus via Preferences / Viewer / Plugins and then configuring the ActiveX + Preview + Office + Web plugin. Another alternative would be to try a different PDF viewer, such as Adobe Reader or Sumatra. (In Sumatra's case, it doesn't install a preview handler by default, but there's an option to do so in the installer.)

Leo, yes if I can link to this account, that would be better.

I have installed Acrobat Reader, but how do I have Opus use this as the viewer?

.pdf is shown as being assinged to Nitro PDF in configuration of AtiveX .....

OK, I've transferred the link from the old account to the new one.

The viewer is usually the program that has been associated with PDF files (assuming it includes a preview handler), but you can change which one is used via the ActiveX + Preview + Office + Web plugin I mention. (That plugin is like a meta-plugin which allows preview handlers written for File Explorer / Outlook / etc. to work within Opus.)

Is there also an "Adobe PDF" or "Adobe PDF for Vista" or similar entry in the list? Try adding .pdf to one of those and clicking Apply, then click on a PDF, or close & re-open the viewer with a PDF already selected.

For some reason, Adobe Reader tends to install two preview handlers, only one of which works, so try both if there are two. They also still have "for Vista" in the name even though it's for Windows 7/8/10 as well.

Thanks Leo,

Adding .pdf to the Adobe PDF for Vista (a bit non-intuitive!) seems to make things work.

Odd that I have Acrobat and Reader installed and there is no entry for either of these.

Thanks. Greatly appreciated - I use viewer about forty times a day.

"Adobe PDF for Vista" is Adobe Reader. Adobe are just bad at naming things. :slight_smile:

Acrobat doesn't include a viewer at all.