0 license(s) available Message

[Alan_PNLS]

I recently deactivated and deleted many users on Zoom's User Management console. But I can't assign license (not Basic) to any new user.
Ehen I clicked on the License button, this message showed up:
0 license(s) available. Buy More Licenses

I've searching on this issue but haven't found any answer. Any comments or helps would be greatly appreciated.