TFormula no longer readable

Hi everybody,

since the upgrade to ROOT 6.14 we observe the following warning messages popping up if TF1 objects are loaded from a TFile

Expression passed to Cling:
Double_t TFormula____id10167864354852591493(Double_t x,Double_t *p){ return (p[0]/(1+TMath::Exp(-p[1](x[0]-p[2])))) ; }
Error in <TFormula::Streamer>: number of dimension computed (1) is not same as the stored value (0)
csc_f : ([0]/(1+ TMath::Exp([1]*(x[2])))) Ndim= 1, Npar= 3, Number= 0
Formula expression:
([p0]/(1+TMath::Exp([p1]*(x[p2]))))
List of Variables:
Var 0 x = 0.000000
List of Parameters:
Par 0 p0 = 0.000000
Par 1 p1 = 0.000000
Par 2 p2 = 0.000000

I've tried a very naive approach of reading out the file in python and then copy the content to another new file made in ROOT 6.14. However, I then observe these errors if I try to  read the new file afterwards

input_line_270:2:10: error: redefinition of 'TFormula____id10167864354852591493'
Double_t TFormula____id10167864354852591493(Double_t x,Double_t *p){ return (p[0]/(1+TMath::Exp(-p[1](x[0]-p[2])))) ; }
^
input_line_232:2:10: note: previous definition is here
Double_t TFormula____id10167864354852591493(Double_t x,Double_t *p){ return (p[0]/(1+TMath::Exp(-p[1](x[0]-p[2])))) ; }
^
input_line_271:2:10: error: redefinition of 'TFormula____id10167864354852591493'
Double_t TFormula____id10167864354852591493(Double_t x,Double_t *p){ return (p[0]/(1+TMath::Exp(-p[1](x[0]-p[2])))) ; }
^
input_line_232:2:10: note: previous definition is here
Double_t TFormula____id10167864354852591493(Double_t x,Double_t *p){ return (p[0]/(1+TMath::Exp(-p[1](x[0]-p[2])))) ; }
^
input_line_272:2:10: error: redefinition of 'TFormula____id10167864354852591493'
Double_t TFormula____id10167864354852591493(Double_t x,Double_t *p){ return (p[0]/(1+TMath::Exp(-p[1](x[0]-p[2])))) ; }
^
input_line_232:2:10: note: previous definition is here
Double_t TFormula____id10167864354852591493(Double_t x,Double_t *p){ return (p[0]/(1+TMath::Exp(-p[1](x[0]-p[2])))) ; }

I'll attach the file of concern and the script which I used to remake the file to this thread. Can you have a look and tell me what I've done wrong?

Many thanks,

Johannes