I'm getting the following message after the installation of MCA-1.8-5.1.1.1-universal and RadixCore-1.8-2.1.0-universal in the mod folder:

Forge Mod Loader has found a problem with your minecraft installation
The mod listed bellow does not want to run in Minecraft version 1.8.9
Minecraft Comes Alive (MCA) wants Minecraft [1.8,1.8]
The file 'ForgeModLoader-client-0.log'contains more information

Apparently you can't run this mod on 1.8.9. Try it with 1.8.8 and below.

ummm. Any future update in mind?

I'm not a developer, just a person who pretends to know quite much about this mod.

Install Forge for 1.8.8 or below, maybe?

I have a licensed version for windows, in minecraft website I don't see where download a previous version for windows. Any idea?

Nope. I tried several versions without success. Thanks for you help.

You must use the base version of Minecraft 1.8. Currently no update is planned, as there's only 20 something mods that have updated thus far. Not really any benefit to updating, either.

If in doubt, use the installer at the bottom of this page: http://www.radix-shock.com/mca--download.html