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:
Try again to convert an HTML page to PDF from Firefox or Chrome.
The resolution steps should work. However, if you're still running into issues, report your problem to Adobe using the Feature Request/Bug Report Form.