I went there and downloaded 173 on your advice and the readme file says "Also this version do not support hardware antialiasing, because of method to capture scene depth (vendor hack),"
I have no idea if this will solve it for you, but my own issue with Merge Plugins crashing every merge was solved by reading a post from someone who said you need to wait extra long after Merge Plugins says the merge is already done to close the Merge window. When I waited an extra amount of time to close the merge, Merge Plugins did not crash.
I am having the same problem. I'm using Merge Plugins on Fallout: New Vegas and every time I try a merge it crashes. I've tried deleting my Merge Plugins profile as was suggested to someone else in the past but this does not help.