# ERROR:Eval --RooAbsReal::logEvalError message in Roofit

Hello RooFit experts

I am using root_v5.22.00 to compile and execute this code (attached)
the idea is :
I am constructing my RooAbsPdf of RooAbsReal that depends on 4 variables time+3 angles .
the problem is :
I get this error message constantly :

```[#0] ERROR:Eval -- RooAbsReal::logEvalError(term_U_B) evaluation error, origin : RooBDecay::term_U_B[ convSet=(res_gauss_conv_exp(-@0/@1)*cosh(@0*@2/2)_t_tau_DG_[term_U_B], res_gauss_conv_exp(-@0/@1)*sinh(@0*@2/2)_t_tau_DG_[term_U_B], res_gauss_conv_exp(-@0/@1)*cos(@0*@2)_t_tau_dm_[term_U_B], res_gauss_conv_exp(-@0/@1)*sin(@0*@2)_t_tau_dm_[term_U_B]) t=t tau=tau dgamma=DG f0=0.000000 f1=sinh_U_n_B f2=cos_U_p_B f3=sin_U_n_B dm=dm ] message : p.d.f value is less than zero (-0.000188), forcing value to zero ```

The error claims that I am using a negative Pdf (term_U_B ), the term_U_B is a RooAbsReal and not a RooAbsPdf , so I think it is perfectly fine for this term to have a negative values.
Moreover, this code works perfectly fine with root_v5.18_SL4 and give the proper results.

I wonder if you can help me fix this problem appeared in the new root version
Thanks very much for your help , and I am sorry for the long code
test.C (10.2 KB)

I have just post this in the ( Stat and Math Tools forum)
sorry for posting in the wrong forum