I'm afraid it doesn't work, at least on my PC. I firstly tried your way. I installed FST once and then cloned it three time, so I got 4 different folders for it, as you can see here.
I clicked on "Allow multiple..." option as I opened them one by one. The first three run without problem, but when I tried the fourth one, this message popped up:
It simply crashed!
Then I tried what Popov suggested. I run the same FST several times (again "Allow multiple.." option activated. Again, the same result but with a different window error: This one:
So my question is, why ALWAYS the last run/copy makes the program crashes. Is there any limit of open executions simultaneously? Apparently not, but it happens to me once and again
Thank you very much for your response.