Is this an issue with a particular PDF file or with all the PDFs? Please try with a different PDF file and check. If the file is stored on a shared network/drive please download it to your computer locally and then try again.
Also try to repair the installation from the help menu (Win Only) and see if that works.
You may also try to turn off the protected mode for testing. Go to Edit > Preferences > Enhanced Security > Uncheck 'Enable Protected mode at startup' > Turn Off the Protected mode and Uncheck Enhanced Security > Click OK and reboot the computer.
Note: Please turn on the security after testing to avoid any security risk.
You may also try to create a new test user profile with full admin rights in Win and try using the application there and check.