I found that Norton 360 thought the LilyPond executable was a virus on Windows 11. The symptom was that Lilypond exits with a code of 1 and no PDF is created. In case this happens to anyone else, here are the steps to exclude LIlyPond from Norton's real time protection:
1) Open Norton 360 app 2) Click on Open next to Device Security 3) Click on Settings 4) Click on Antivirus 5) Click on Data Protector 6) Click on Configure next to Process Exclusions 7) Click on Add 8) Navigate to where you installed LilyPond and in the bin folder, choose lilypond.exe My hope is this will help others in the same situation. -- Knute Snortum
