I am unable to reproduce the crash you are seeing in slic with Pelle's "new" detector, using the *dev* version of the simulation e.g. building from
which has these versions
[1008 $] slic -v
I run this command
slic -g detectors/HPSTracker2014-v0.lcdd -i stdhep/ap2.2gev075mev.stdhep -x -O -r 99999999
and it gets past the event which crashes on your setup.
I'm going to see how far it gets into this job (at 4000 events and counting). It looks to me like it should succeeed without crashing.
So the immediate solution here is using this dev setup, which is v05-00-00, instead of the HPS specific config.
The 3.x version of slic that we use currently is outdated, and continuing to use this is problemmatic, as it is difficult to patch at this point. It would require making a separate development branch of one of the old, released tags of slic and then making specific code changes and releases on that branch. Even then, I'm not sure it would be easy to fix the crash that is happening only with changes to SLIC, as it could be related to Geant4 internals which we have no ability to modify without upgrading the Geant4 version (e.g. generally the stability of G4 has been improving with the releases lately so this problem you're having probably just goes away).
Upgrading to the new version, the Geant4 will be different, as the old one is 9.6.p01, and the current build uses the 10.0.2 release. I can't tell you whether this would be a "problem" or not, but certainly the physics results could change between major versions. We would want to study this.
Perhaps the ECAL Commissioning data could help us study this, at least for energy depositions and resolutions in the crystals. It would be interesting to see whether this data agrees with the MC output from the current version of slic.