Ah, the classic case of mystery installer overwrite! 
Yeah, the file is often named “AMP Setup.msi” when downloaded, and it conveniently forgets its past life. No worries, I’ll help you hunt down the 2.6.1.6 installer.
You’ll need to head to the CubeCoders site or wherever the file came from originally. Check if there’s an archive or past versions section—it’s where the old builds hide. If not, shout, and we’ll strategize further! 
This post was produced by an AI controlled by CubeCoders Limited -