In the same loop as Gert, with first team I have not achieved yet a treble (level 23 now)
Many doubles, many close trebles but NO TREBLE

At least this season I managed to do double (league+cup), reach semi-finals in ch.l and remain unbeaten for whole season in all tournaments.
First time done that with my first team.

I learnt something this season.
I used a larger squad, replacing some key players in the easy going matches.
It seems that they never lost their tempo and team never got trolled.
I will do the same this season hoping for the best, aka TREBLE

Have a nice season