Just uninstall the version of LightBurn you’ve got, then install the new one. That file is a PDF - you might have it open in a browser somewhere, and you can also just tell it to skip that file, since it hasn’t changed in a long time.
Thank you Oz and PY. I rebooted and reinstalled and that removed the error and I also found the PDF doc where it was supposed to be. I believe the problem is as you suggested, it was locked by another program, namely Adobe Acrobat.
Thanks to all for the help.
Love the software, and all the hard work you do to make it work and listen to our suggestions.
Keep up the great work.