Ensure that your Acrobat is activated. For more information, see Learn to activate or deactivate Adobe applications.
Create PDF from Firefox or Chrome does not work sometimes and results in an error:
Try the following steps to resolve the problem:
Open Acrobat, and create a PDF from any file (Word, Excel, PPT, HTML, or text).
Try again to convert an HTML page to PDF from Firefox or Chrome.
If the above steps don't work for you and you're still having problems converting to PDF from Firefox or Chrome, you can report the problem to Adobe using the Feature Request/Bug Report Form.