Thank you for your reply, Stefano.
I have just made a clean install of PandaRoot using
svn co https://subversion.gsi.de/fairroot/pandaroot/trunk
to make sure that I am using the most recent version (revision 15614) and the problem seems to still occur. I am using sim, digi, reco and pid macros from the macro/pid folder and added EvtGen Direct in the sim macro in order to simulate the decay X(as Psi')-> j/psi pi pi with j/psi -> e+ e-.
I have looked at the digi_sttcombi.root and I can find a branch called EmcDigi, but do not see anything called TCA within that branch. Where should I find it?