PDF files in Viewer

I can no longer view PDF Files in the Viewr,,,, They seem to present as some sort of metadata or text file?
it used to work ok
I have always used PDF X-change as my pdf viewer. all good on my other PC but as above on this one????

Try reinstalling the PDF viewer.

If it doesn't work in Explorer either, ask for support from the makers of the viewer.

Thanks for prompt Reply,,,
It is all fine in Windows Explorer

if I Open the File from dopus ,,, it all opens fine into PDF -Xchange Editor.
If I open the Viewer window within Dopus,,, tit does not display as a PDF file. Looks more like a text file.
If I open as a viewer in windows explorer all is fine.

If I open on main PC in Dopus Viewer,,, all is fine.
Ive checked all the Dopus Settings (tkes a while to do) on both devices and all is same.

Have you tried reinstalling the PDF viewer? (Rebooting afterwards may also help, in case anything is being cached from the previous state.)

PDF viewer/editor problems are usually because two pieces of PDF software are fighting over the registry settings.

Last night I did this,,,
Uninstalled PDF-Xchange Editor. Reinsllled and Rebooted ,,,, Problem still there.
Uninstalled Dopus. Reinstalled and Rebooted,,, Still have the Problem.

If you go to Preferences / Viewer / Viewer Plugins, select the ActiveX + Preview + Office + Web plugin and click Configure, is PDF listed against the PDF-XChange viewer in there?

In Explorer, is the viewer able to scroll, and not just showing the first page or anything like that?

Thanks Leo,,,
That was the problem,,, PDF-Xchange was selected as the Previewer but there was No Extension selected.
Ive added .pdf and all is well.