Missing Drop Shadow effect in AE

Just Reset all preferences  

It might be that After Effects disabled it because of some errors. That happened to me. So, what you'll need to do here is go to Effects > Manage Effects... > Disable checkmar for Only Show Third-Party Effects and find it (or type in search) in the list and enable it. I hope that's the case and will help.

This suggests that the plugin is no longer in the expected folder.  Have you moved or deleted any files within the After Effects folder?

On your Mac, the standard location to find plugins for a current version of AE is 

Macinosh HD > Applications > Adobe After Effects 2023 > Plug-ins > Effects

The file name is Drop_Shadow.plugin

If it isn't there, try searching your hard drive for that file name, in case you've inadvertantly moved it.  If you find it elsewhere , put it back in the correct place and restart After Effects.

If you can't find it at all, use the Adobe CC Manager to re-install After Effects.

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post if it helps you get responses.

<moved from using the community>