Try clearing the Help caches. Probably the easiest way is via the free OnyX app.

Quit Help, then select the Maintenance icon in the OnyX toolbar, then the Rebuild tab. Towards the bottom, check (only) the Help Viewer menu box.

The M+ OUTLINE FONTS are a font family under the Free license. You can use, copy, and distribute it, with or without modification, either commercially and noncommercially.

help page for compromised accounts to find out how to fix it quickly

JMusic osx