diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java b/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java
index b1c0776513c1..0163a3b895a4 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java
@@ -219,17 +219,19 @@ public class StudySerializationUtils {
             for (Element placeholder : getChildList(taskFileElement, ANSWER_PLACEHOLDERS)) {
               Element valueElement = new Element(SUBTASK_INFO);
               addChildMap(placeholder, SUBTASK_INFOS, Collections.singletonMap(String.valueOf(0), valueElement));
-              for (String childName : ContainerUtil.list(HINT, ADDITIONAL_HINTS, POSSIBLE_ANSWER, SELECTED, STATUS, TASK_TEXT)) {
-                Element child = getChildWithName(placeholder, childName);
+              for (String childName : ContainerUtil.list(HINT, POSSIBLE_ANSWER, SELECTED, STATUS, TASK_TEXT)) {
+                Element child = getChildWithName(placeholder, childName, true);
+                if (child == null) {
+                  continue;
+                }
                 valueElement.addContent(child.clone());
               }
               renameElement(getChildWithName(valueElement, TASK_TEXT), PLACEHOLDER_TEXT);
-              List<Element> additionalHints = ContainerUtil.map(getChildList(valueElement, ADDITIONAL_HINTS), Element::clone);
               Element hint = getChildWithName(valueElement, HINT);
               Element firstHint = new Element(OPTION).setAttribute(VALUE, hint.getAttributeValue(VALUE));
               List<Element> newHints = new ArrayList<>();
               newHints.add(firstHint);
-              newHints.addAll(additionalHints);
+              newHints.addAll(ContainerUtil.map(getChildList(placeholder, ADDITIONAL_HINTS, true), Element::clone));
               addChildList(valueElement, "hints", newHints);
             }
           }
diff --git a/python/educational-core/student/testData/migration/4.xml b/python/educational-core/student/testData/migration/4.xml
index 944ffd640b2e..b0c11ff543b8 100644
--- a/python/educational-core/student/testData/migration/4.xml
+++ b/python/educational-core/student/testData/migration/4.xml
@@ -69,11 +69,6 @@
                                           <value>
                                             <AnswerPlaceholderSubtaskInfo>
                                               <option name="hint" value="hint 1"/>
-                                              <option name="additionalHints">
-                                                <list>
-                                                  <option value="hint 2"/>
-                                                </list>
-                                              </option>
                                               <option name="possibleAnswer" value="Liana"/>
                                               <option name="selected" value="false"/>
                                               <option name="status" value="Solved"/>