diff --git a/cvat-core/src/annotations-objects.ts b/cvat-core/src/annotations-objects.ts
index 320a270cb54..defcf7dbbad 100644
--- a/cvat-core/src/annotations-objects.ts
+++ b/cvat-core/src/annotations-objects.ts
@@ -2918,7 +2918,7 @@ export class SkeletonTrack extends Track {
                 parentID: this.clientID,
                 readOnlyFields: ['group', 'zOrder', 'source', 'rotation'],
             });
-        }).sort((a: Annotation, b: Annotation) => a.label.id - b.label.id);
+        }).filter(Boolean).sort((a: Annotation, b: Annotation) => a.label.id - b.label.id);
     }
 
     public updateFromServerResponse(body: SerializedTrack): void {
diff --git a/cvat/apps/dataset_manager/annotation.py b/cvat/apps/dataset_manager/annotation.py
index d82ce747956..a0f5f538022 100644
--- a/cvat/apps/dataset_manager/annotation.py
+++ b/cvat/apps/dataset_manager/annotation.py
@@ -91,7 +91,7 @@ def has_overlap(a, b):
 
             prev_shape = shape
 
-        if not prev_shape['outside'] and prev_shape['frame'] <= stop:
+        if prev_shape is not None and not prev_shape['outside'] and prev_shape['frame'] <= stop:
             return True
 
         return False
@@ -552,6 +552,8 @@ def _calc_objects_similarity(obj0, obj1, start_frame, overlap, dimension):
             return 0
 
     def _modify_unmatched_object(self, obj, end_frame):
+        if not obj["shapes"]:
+            return
         shape = obj["shapes"][-1]
         if not shape["outside"]:
             shape = deepcopy(shape)