Since this is not a common issue and there’s much we don’t know about your setup—like anything, we need more information.

https://makemusic.zendesk.com/hc/en-us/community/posts/215729367-General-Discussion-House-Rules 

my apologies, this is my first post and i didn't know about the house rules. I'm running windows 10 x64, Finale v27. pretty much just upgraded last week. I haven't done anything special when setting up a new document. All I've done is add my instruments from the setup wizard. I don't mess with any human playback or...any settings for that matter. Pretty much just right-out-of-the-box vanilla v.27. and when using tremolos, I'm using shift+8. When using the 1-line bass drum, im using the "bass drum roll" when placing notes. Is there anything else you would like to know?

edit: when using easy tremolos (completely separate issue), note heads are replaced with letters. Do they just need to like...patch this version since its so new?

Sadly, not all plug-ins have been updated to work with SMuFL fonts (that likely loaded automatically if you created a new file in v27). That explains the easy tremolo result, but that plug-in is designed (IIRC) for two-pitch trem's rather than rolls.

Are you using the MIDI Bass Drum from SoftSynth or the Aria/Garritan version?

The single line bass drum appears to be garritan.

just added a Bass Drum from GPO5 (and tried again with the GIfF included with Finale 27). In both case, adding a triple-slash tremolo from the Articulation tool automatically produces the Bass Drum roll with dynamics. (Presumably, for a Bass Drum, one doesn't need to use the Easy Tremolo tool at all.

I discuss your other tremolo issue at

https://makemusic.zendesk.com/hc/en-us/community/posts/4403282898071-Tremolos-don-t-work-in-new-files-27