Believe it or not, this is a very common issue with a simple fix! 


Here are some instructions sent to us by CDK:


 !!!!! CLOSE CDK DRIVE BEFORE GOING ANY FURTHER!!!!
 
 
First, open Adobe Reader on the affected computer. Click on ‘Edit’ at the top, then Preferences.
 
 
 
Then, navigate to the Security (Enhanced) section and uncheck the ‘Enable Protected Mode At Startup’ box. Click Ok to save changes and have the user restart CDK.
 
 
 
 
After restarting your computer, you should be able to print from PDFs again.


Hopefully, this helps!