add test for null value before trying to get size.
@@ -918,7 +918,7 @@ public class XmiCasSerializer {
case LowLevelCAS.TYPE_CLASS_STRINGARRAY:
if (cds.isStaticMultiRef(featCode)) {
attrValue = cds.getXmiId(featValRaw);
- } else if (cds.cas.ll_getArraySize(featValRaw) == 0) {
+ } else if (featValRaw != CASImpl.NULL && cds.cas.ll_getArraySize(featValRaw) == 0) {
attrValue = ""; //https://issues.apache.org/jira/browse/UIMA-5558
} else {
stringArrayToElementList(featName, featValRaw, childElements);
