I checked my files and the "rtl_sdr.txt" file has a creation date of 5/18/2018.
That is also the "Date Modified" for all of the MultiPSK "PAIR#.TXT" and "??.SER"
files in the MultiPSK directory. There are other files dated the same. It is probably
the date of a previous MultiPSK installation on my machine. When I update
MultiPSk, I copy only recently changed files to the MultiPSk directory to prevent
overwriting data that I have collected or modified, unless Patrick says otherwise.
I'm sorry, but that is all know about it's source.
Good luck on the troubleshooting.