From the program menue PMDG I can read PMDG777 Introduction and PMDG Tutorial1 starting the Operations centre for the 777 I see in Documentation 6 documents but I cannot open them PMDG777 Introduction PMDG Tutorial1 Flight Crew Operations manual etc etc. Have I done something wrong or they cannot be opend?

Have I done something wrong or they cannot be opend?

 

Do you have Adobe Acrobat Reader installed?

 

Disregard - try opening them from the folder itself.  Look in your FSX directory - PMDG folder - 777 - Documentation (or manuals, or something like that).

Thank you I will try that tomorrow.

I can open them from the folder you said and when I don't have the box ticked open PDF's  in external viewer in the 777 operations center they open too. So thats solved.

Good day, I know this post is almost 3 years old, but I have encountered the same issue. PDF's will not open via the Operations Center or directly from the relevant PMDG folders. I have the latest Adobe Acrobat Reader. All other non-PMDG documents open normally....Any ideas? I have tried the options as posted above....Platform P3D v3.1.