The search for a "Meteor Client 1.8.9" download from 2021 reveals a significant compatibility conflict:

Feature: Customizable World Map Overlays

One of the most famous open-source utility clients for 1.8.9. Raven B+ Utility / Ghost

Step 2: Installation (Fabric API Required)

Meteor Client runs on the Fabric Mod Loader. You cannot run it on Forge or as a standalone executable. Here is how to set it up: