The program has had enough and is just saying NO!  

Im kidding of course.  I'd restart the computer and printer to clear all the RAM in both of those, then come back and see if its still happening.

Its also possible that last nights update did something wonky and a file was corrupted, you could try using refresh or repair updates.

1. Open ProSeries.
2. From the Updates menu, select Refresh Updates then Refresh Updates for Installed Products.
3. Select Install Now.
4. Once the ProSeries Update Log is shown select Close.
5. Open ProSeries.
6. From the Updates menu, select Update Installed Products.
7. If updates are found select Install Now.
8. If no updates are found select Close.