Well the developers prefer all users to use the latest OS and update to the software, but here is our own archive of pretty much every MyDMX 3 release, try not to use any labelled as "Do not use" or "DNR" or even "beta" if at all possible.
https://www.dropbox.com/sh/4yq..._Pq_OTbNH62bkJa?dl=0