I'm having the same issue as BarkerforEngland.
I tried heal team, save then pulled up FM15, no result, continued, no result.
I tried to manually edit the fitness of one player, I hit save and his fitness levels returned to the same numbers they were before i edited them. I checked fm15, no change whatsoever.
I'm having the same issues as mentioned above with changing any stats/attributes. I save and they return to the value they were before the second i click save and there are no changes in game, even after continuing.
**EDIT**
So as it won't let me delete this, I might as well edit to say that I fixed the problem simply by closing FMRTE and then reopening it. Yes, for some reason I hadn't thought to try that before commenting, my brain is asleep today.