So I promised a friend a little christmas pack with some of my "best of" snow levels for the end of November. I also put in some "special" levels in other tilesets and I thought turning on the "Always Xmas" option in the Flexi-Toolkit would change my Lemming sprites + skillbar for all levels into the Xmas ones ------ no. Everything stays normal and no Christmas Lems or skillbar at all.
Would love a quick fix here as I kinda want to hold my promise of a little Christmas "best of" pack before December :). Sry, I did not count in this problem at all.
Changing the main tileset to Christmas gets me at least the Xmas Lem sprites as a workaround, but that would also change bridge+map colors and stuff which is not always fitting + manually editing every single level again is not fun :(.
This is most likely a bug in the player, not Flexi.
EDIT: Yes, it was a player bug; and fixed for next update.