I also have the problem of bolt maker not working anymore, where it used to work fine for ages, and I must admit a great program.
A few hicups with extra entities, appearing and various things I had to complete with erase and push/pull, but I was driving through 3 different shapes, and sometimes it didn't like putting bolts through the flange of a steel angle joined to 2 flats.
Anyway I think that I have found the problem of the program not working.
I work in mm, and somewhere along the line I changed the precision to 0.
So delete the .txt file, and change the precision to at least 0.0 this then seems to work for any size bolt.