After you update to Acrobat 11.0.01, the serial number dialog appears when you print using the Adobe PDF printer. In some cases, an error message appears that asks you to activate Acrobat. The problem only occurs if all of the following are true: 

• The system is using Acrobat on Windows and has updated to 11.0.01. 
• Acrobat has never been launched.
• The Acrobat serial number language is English only. 
• The operating system language is nonEnglish. 
• The installation was not a UI installation. That is, it was done via the command line or some other enterprise method. 
• You try to print to Adobe PDF. 

Solutions

End-user option

Launch Acrobat for the user at least once before printing to PDF to resolve issue for that user on the machine.

IT-enterprise option

To resolve the issue for all users on any machine, do the following: 

1. Find the registry key HKLM\Software\[wow6432node]\Adobe\Adobe Acrobat\11.0\Language\current\
2. Set the default value to "acrobat.dll."
3. Distribute the setting across you organization via GPO or some other method.