Move from the copied LHEF.h to the LHEF3.h from Pythia8 for the LHEF backedn in the Prophecy4fControl.
This might be an intermediate solution, once the HepMC2 branches are dropped, one can use LHEF.h from HepMC3.
Tag @schaffer @ancuetog @fwinkl @ewelina
Best regards,
Andrii