I've noticed that sometimes when I train a strategy with RULES using multiple cores and WFO, I don't always get .ml files from all the cores. For example I've seen several times since upgrading to 1.88 that I get ml files 1, 2, 4, 5, 7, 8, 10, 11, 13 but files 3, 6, 9 and 12 are missing. There are no error messages when training, so I usually don't realize that this has happened until I run a test and Zorro complains about missing files. The behavior is not consistent, so sometimes I do get all the files, but not always.