diff --git a/source/blender/blenkernel/intern/lib_override.c b/source/blender/blenkernel/intern/lib_override.c
index a2338eb9b39..9dc64365f0c 100644
--- a/source/blender/blenkernel/intern/lib_override.c
+++ b/source/blender/blenkernel/intern/lib_override.c
@@ -1384,7 +1384,21 @@ void BKE_lib_override_library_main_hierarchy_root_ensure(Main *bmain)
       continue;
     }
     if (id->override_library->hierarchy_root != NULL) {
-      continue;
+      if (!ID_IS_OVERRIDE_LIBRARY_REAL(id->override_library->hierarchy_root) ||
+          id->override_library->hierarchy_root->lib != id->lib) {
+        CLOG_ERROR(
+            &LOG,
+            "Existing override hierarchy root ('%s') for ID '%s' is invalid, will try to find a "
+            "new valid one",
+            id->override_library->hierarchy_root != NULL ?
+                id->override_library->hierarchy_root->name :
+                "<NONE>",
+            id->name);
+        id->override_library->hierarchy_root = NULL;
+      }
+      else {
+        continue;
+      }
     }
 
     BKE_main_relations_tag_set(bmain, MAINIDRELATIONS_ENTRY_TAGS_PROCESSED, false);
@@ -1402,7 +1416,7 @@ void BKE_lib_override_library_main_hierarchy_root_ensure(Main *bmain)
       continue;
     }
 
-    lib_override_root_hierarchy_set(bmain, id_root, id_root, NULL);
+    lib_override_root_hierarchy_set(bmain, id_root, id, NULL);
 
     BLI_assert(id->override_library->hierarchy_root != NULL);
   }
@@ -1451,6 +1465,7 @@ static void lib_override_library_remap(Main *bmain,
                                remapper,
                                ID_REMAP_FORCE_USER_REFCOUNT | ID_REMAP_FORCE_NEVER_NULL_USAGE);
   BKE_id_remapper_free(remapper);
+  BLI_linklist_free(nomain_ids, NULL);
 }
 
 static bool lib_override_library_resync(Main *bmain,
@@ -2058,6 +2073,10 @@ static bool lib_override_resync_tagging_finalize_recurse(
 
     CLOG_INFO(&LOG, 4, "Found root ID '%s' for resync root ID '%s'", id_root->name, id->name);
 
+    if (id_root->override_library == NULL) {
+      BLI_assert(0);
+    }
+
     LinkNodePair **id_resync_roots_p;
     if (!BLI_ghash_ensure_p(id_roots, id_root, (void ***)&id_resync_roots_p)) {
       *id_resync_roots_p = MEM_callocN(sizeof(**id_resync_roots_p), __func__);