Sorry to hear that this isn't working like it should. Obviously something has got it muddled. Here are a few things to try:
1. On the Help tab, look for the "Tidu Up" button on the right side. Click that and then once it has removed all the temporary files, try to print again.

2. If that doesn't solve the issue, try printing a different book.
3. If you're still facing the same error, then you can create a log of what is happening and send the resulting file to ptxprint_support @ sil.org (without the spaces). Here's how to create the diagnostic log:
- Close PTXprint
- Open a terminal (on Windows, Search for 'cmd' which should give you a Command Prompt)
- Type cd "C:\Program Files\PTXprint" and press Enter
- Then type PTXprint.exe -l debug
- When PTXprint opens, click Print as usual (you should get the same error message)
- Close PTXprint
- Locate the ptxprint.log file (should be here:
C:\Users\<username>\AppData\Local\SIL\ptxprint\ptxprint.log) and send it to us by email.
If all else fails, let us know which timezone you are in and when we can get in touch via a Zoom support session.