diff --git a/src/entry/Maat_hierarchy.cpp b/src/entry/Maat_hierarchy.cpp
index 6f7b960..3bd14b0 100644
--- a/src/entry/Maat_hierarchy.cpp
+++ b/src/entry/Maat_hierarchy.cpp
@@ -474,7 +474,8 @@ static void Maat_hierarchy_group_free(struct Maat_hierarchy* hier, struct Maat_h
 	}
 	igraph_vector_destroy(&v);
 	assert(group->top_group_ids==NULL);
-	igraph_delete_vertices(&hier->group_graph, igraph_vss_1(group->vertex_id));
+	//We should not call igraph_delete_vertices, because this is function changes the ids of the vertices.
+	//igraph_delete_vertices(&hier->group_graph, igraph_vss_1(group->vertex_id));
 
 	
 	HASH_DELETE(hh_group_id, hier->hash_group_by_id, group);
diff --git a/src/entry/Maat_rule.cpp b/src/entry/Maat_rule.cpp
index 858c662..75a1bfa 100644
--- a/src/entry/Maat_rule.cpp
+++ b/src/entry/Maat_rule.cpp
@@ -34,7 +34,7 @@
 #include "stream_fuzzy_hash.h"
 #include "gram_index_engine.h"
 
-int MAAT_FRAME_VERSION_3_0_20200619=1;
+int MAAT_FRAME_VERSION_3_0_20200702=1;
 
 int is_valid_table_name(const char* str)
 {