I've just installed 2.19.52 and put it into Frescobaldi. On converting two of my files I got 2 oddities:
1) (fairly serious) It converted to 2.19.49, not .52 - I changed the version number by hand, but I'd have thought that this should be automatic. The message at the bottom of the file is:
2) (annoying) It inserted a blank line between each of the original lines in the file. Could this be because I'm using Windows and the CR-LF newline is confusing it? This would appear to be a bug.