how to declare Pointer to string list structure in c++

hi i am getting runtime exception for Pointer to string list structure


itis showing exception in the line:

"UF_STRING_t * sectionEditData=NULL;"

Code:

void defGeometry::ReplaceSpline(std::vector<struct geometricSection>sections)
{
	int j=1;
	tag_t PartTag=NULL_TAG;
	tag_t feat_tag=NULL_TAG;
	char feat_name[]="THROUGH";
	UF_STRING_t * sectionEditData=NULL;
	PartTag=UF_PART_ask_display_part();
	UF_CALL(UF_OBJ_cycle_by_name_and_type (PartTag, feat_name, UF_feature_type, FALSE, &feat_tag));
if(!feat_tag)
	{
		sysLogPrint("Failed to create spline !");
}
else
{
	sysLogPrint("s.t=%d",feat_tag);
	if(!UF_CALL(UF_OBJ_delete_object(feat_tag)))
	{
		sysLogPrint("sucess!");
	}else
	{
		sysLogPrint("failed!");
	}
}
for(int i=0;i<ActionSide.NumberOfSections;i++ )
{
	UF_MODL_init_string_list(&sectionEditData[i]);
	UF_MODL_create_string_list(1, 4, &sectionEditData[i]);
	sectionEditData[i].string[0]=4;
	sectionEditData[i].dir[0]=UF_MODL_CURVE_START_FROM_BEGIN;
		sectionEditData[i].id[0]=sections[i].section_tags[0];
		sectionEditData[i].id[1]=sections[i].section_tags[1];
		sectionEditData[i].id[2]=sections[i].section_tags[2];
		sectionEditData[i].id[3]=sections[i].section_tags[3];
	if( j<=3)
	{
		UF_CALL(UF_MODL_replace_feat_strings (feat_tag, UF_MODL_STRING_REPLACE, &sectionEditData[i], 1, j++));
	}
	else
	{
		UF_CALL(UF_MODL_replace_feat_strings (feat_tag, UF_MODL_STRING_ADD, &sectionEditData[i], 1, (j++)-1));
	}
	UF_MODL_update ();
	free(sectionEditData);
}
};

Is the defGeometry object that this member function is being called on valid? Can you check the this pointer at the time of the exception and see if it is null or otherwise corrupted?

That simple assignment causing an exception probably indicates that the memory is corrupted somewhere else.