If your error message looks like this:

Try printing again and review your Adobe Acrobat prompt that looks similar to this:

Ensure that you have chosen the "Save File" radio button and check "Do this automatically", then select OK. Your file should save and print normally now.

If you do not get the option for the prompt, Adobe or another program may have been set as the default program for handling Kno2 files, or you may not have the Kno2 Client installed. Please verify you have the Kno2 Client installed and that it is the default program for handling Kno2 files.