My plugins are not working

[fkij]

I installed some plugins on my 1.21 smp, none of them worked. One of them were called RankGrant+ and it said installed on the addons page. But when I do /plugins in my server, it didn't show that the plugin was in the game plus the commands didn't workand for some reason i couldn't take a screenshot of this but when I did /plugins it said exactly this:

Server Plugins (2):

Bukkit Plugins:

- MinehutPlugin, ViaVersion

(the two plugins above were preinstalled and are not of the 3 plugins that didn't work)

[Mwuhh]

I recommend uninstalling the ones you installed through the addons panel Then find and install the plugins you want onto your computer, then from there, manually drag and drop them into the plugins folder -> Then restart your server! 

This is one place to get the plugin you are showing in the picture: https://www.spigotmc.org/resources/rankgrant-give-ranks-through-intuitive-gui-menus-grant.63403/
 

[UnpaidIntern]

I had exactly the same problem with 2 plugins not working and not showing up in /plugins menu.   I tried this solution (deleted plugins installed via add-ons tab, then restarted server just to be safe) then downloaded 2 plugins to computer (FastAsyncWorldEdit from curseforge and GriefPrevention 16.18.4 from bukket....  to be clear).

Fast AsyncWorldEdit "successfully uploaded"with drag n drop into my MH server's file manager plugins folder, and can be seen by typing (in-game) command /plugins (it only shows "bukket plugins" , and (by doing // in chat and testing an edit) we could confirm it works!

When trying to drag n drop GriefPrevention into my MH server's file manager plugins folder, I get a message "File already exists" - but i checked every folder and it is not there (and r-clicking golden shovel in game does not do anything).

Any advice is much appreciated.