It should work if you installed the MG VSTs and Ableton/Reaper scan the location where you have the .dll.
Sometimes people forget that MG is an effect, not an instrument - so you should find it when applying effects to audio tracks (not midi tracks)
MG is a VST2 whereas most newer VSTs are VST3. VST2 and VST3 files usually have different file locations to scan. So make sure MG is in your VST2 folder.
Make sure you scan the location of the MG 64bit VST if your DAW is 64bit. Scan the location of MG 32bit VST if your DAW is 32bit.