@Andrew Parsloe --------------------------------------- When you reinstalled LyX did you retain your preferences? If so, then try renaming the file
C:\Users\<your name>\AppData\Roaming\LyX2.3 to (say) C:\Users\<your name>\AppData\Roaming\LyX2.3old and then start LyX. This will create a pristine LyX2.3 folder and subdirectories. See if that cures the article.cls problem. I've had occasions when something has gone wrong in my preferences file and this has done the trick. If it does solve the problem, then copy back the subdirectories one by one from LyX2.3old to the new LyX2.3 and start LyX after each copy to see when the problem re-emerges. --------------------------------------- Yes specifically: Zip Lyx user dir stuff in AppData Uninstall LyX with check box to remove all user data I did think of that one. Note that I may have recently figured out that it is a Win 10 Pro/Enterprise and possibly Home (though I cannot verify) permissions change between folders on Win 10 like between MikTeX and LyX dirs. Running LyX in Administrator mode now allows me to generate PDF on the Win 10 Enterprise Machine... I will now try the trick on the Win 10 Pro box.
