When you process DDIC structures while an ABAP program is running, the system may issue runtime errors or even terminate the process with core dump if there is an inconsistent DDIC load ("nametab").
The problems are due to previous problems in the DDIC, that is, unresolved inconsistencies in dependent structures after DDIC changes or internal errors in the DDIC.
The processing of the structures during the ABAP runtime does not always expect inconsistent DDIC structure descriptions and, therefore, issues followup errors.
Kernel patches are available for kernel Release 620 that implement the missing security checks (kernel patch number 945 with the patch text, "ABAP: Inconsistencies in structure views"). A runtime error will occur if the system encounters these inconsistencies.
Otherwise, if inexplicable terminations occur while you process DDIC structures, you should always check the consistency of the relevant DDIC structures (either with transaction SE11 or with the RSDDCHECK check program as described in note 595069).