TFormula::Streamer error with newer ROOT version

Hi again,

after upgrading from 6.08/06 to 6.14/04 we see error if a TFormula is read from a file created with the older ROOT version. For example

Error in <TFormula::Streamer>: number of dimension computed (1) is not same as the stored value (0)
               myfunc : [0]*exp(-[1]*x)+[2]+[3]*x Ndim= 1, Npar= 4, Number= 0 
 Formula expression: 
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 
Par   3                   p3 =    0.000000 
Expression passed to Cling:
	Double_t TFormula____id3578509394144759005(Double_t *x,Double_t *p){ return p[0]*TMath::Exp(-p[1]*x[0])+p[2]+p[3]*x[0] ; }

This one I created by running (373 Bytes) two times:

source /cvmfs/
source /cvmfs/
python read

It seems the functions are usable but it does make us a bit suspicious. Is this a known problem/feature? I tested a few other version and this error seems to appear when changing from 6.12 to 6.14

ROOT Version: 6.14/04
Platform: Ubuntu 16.04
Compiler: GCC 8.2


This is a known problem with ROOT 6.12 and 6.14, but it has been fixed now in both the master version and 6.14.06. See

This will work fine:

. /cvmfs/ 
python read


Thanks, that’s all I need to know

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