I contacted support about the issue of the latest version of Acid 10 crashing when rendering. I was told that the developers were working on it. Please upload an old version so that I can roll back to a working copy
These are user to user forums, not a contact for any Magix staff, so it is highly unlikely that anyone here can help you with this.
Why not reply to the support ticket you already have and ask for access to download an earlier version? Whether such access is possible I have no idea.