The new release of xspec uses AtomDB 2.0 for the various apec models. Since AtomDB 2.0 includes all elements to Zn there are a couple of issues to note.
1. New models vvapec and bvvapec allow all AtomDB 2.o elements to be varied independently.
2. By default the apec, bapec, vapec and bvapec models set to Solar the abundances of the elements included in AtomDB 2.0 but not in earlier versions (we refer to these as the trace elements). To set these abundances to zero use "xset APEC_TRACE_ABUND 0.0". The trace element abundances can be set to any value or linked to the abundance of one of the more common elements e.g. "xset APEC_TRACE_ABUND Fe".