Hi Sohel,
In Office, any attempts to open an embedded file for which the relevant application is not available will cause this error message.
So I'd suggest investigating from the "relevant application" side first. Is Adobe Acrobat XI the default program of .pdf files? Please try to repair Adobe Acrobat, this will recreate the registry keys and copy the approriate
files into system again (Or simply remove and reinstall the latest version) and then check again.
Please also try in Word Safe Mode, and see if issue persists. Some third party add-ins might also cause this issue:
Press Win + R and type "winword.exe /safe" in the blank box, then press
Enter.
Regards,
Ethan Hua
TechNet Community Support
It's recommended to download and install
Configuration Analyzer Tool (OffCAT), which is developed by Microsoft Support teams. Once the tool is installed, you can run it at any time to scan for hundreds of known issues in Office
programs.