Make sure you download them directly from the buddy store using your authenticated and purchased account, afterwards restart Honorbuddy and let it download then check plugins tab. If you're using a stolen key/resold key you're SOL because I don't support those who don't support the dev team.
Can you link it to me please. There are on occasion a plugin or two not supported on the store. I may be able to help, it could be a directory issue you're experiencing.