Geant4 version 10.3 and 10.5 compatibility

I used to work with my code under version 10.3 . Now, after update to 10.5 instead of one (expected) output file, I got three of them (_t0,_t1… etc) . I guess it is some issue of multithreading and not merging all ntuples to one tree. What is the problem, and what I have to change now?

Thank you

The ntuple merging has to be activated by calling:

In 10.5, the default mode for ntuple merging was changed to row-wise in order to preserve an “event point of view” (the n-tuple rows) after merging. But this does not change the fact, that the ntuples are not merged by default. I think that the default was the same in 10.3.

See also more details in the Application Developers Guide,
section on parallel processing