diff --git a/source/ecs/id_manager.d b/source/ecs/id_manager.d
index c5b521b..60f9d5c 100644
--- a/source/ecs/id_manager.d
+++ b/source/ecs/id_manager.d
@@ -11,7 +11,7 @@ struct IDManager
             m_ids_array.add(Data());
         EntityID id;
         id.id = m_next_id;
-        id.counter = ++m_ids_array[m_next_id].counter;
+        id.counter = /*++*/m_ids_array[m_next_id].counter;
         m_next_id = m_ids_array[m_next_id].next_id;
         if (m_next_id == uint.max)
             m_next_id = cast(uint) m_ids_array.length;
@@ -23,6 +23,7 @@ struct IDManager
         Data* data = &m_ids_array[id.id];
         if (data.counter != id.counter)
             return;
+        data.counter++;
         data.next_id = m_next_id;
         data.entity = null;
         m_next_id = id.id;
diff --git a/source/ecs/manager.d b/source/ecs/manager.d
index 8477254..4cdb8e7 100644
--- a/source/ecs/manager.d
+++ b/source/ecs/manager.d
@@ -118,10 +118,10 @@ class EntityManager
                 foreach (i; 1 .. (Parameters!(Sys.update)).length)
                 {
                     ret ~= "
-                        static if(isPointer!(types[" ~ i.to!string
-                        ~ "]))
+                        static if(isPointer!(types[" ~ i.to!string ~ "]))
                         {
-                            comp = components_map.get(PointerTarget!(types[" ~ i.to!string ~ "]).stringof, ushort.max);\n
+                            comp = components_map.get(PointerTarget!(types["
+                        ~ i.to!string ~ "]).stringof, ushort.max);\n
                             if(comp == ushort.max)assert(0,\"Can't register system \\\"" ~ Sys.stringof
                         ~ "\\\" due to non existing component \\\"\"~types[" ~ i.to!string ~ "].stringof~\"\\\".\");
                             system.m_optional_components[opt++] = comp;
@@ -220,7 +220,7 @@ class EntityManager
         {
             mixin(genCompList());
         }
-        
+
         ushort sys_id = systems_map.get(Sys.stringof, ushort.max);
         if (sys_id < systems.length)
         {
@@ -257,7 +257,7 @@ class EntityManager
 
     Sys* getSystem(Sys)()
     {
-        return cast(Sys*)systems[Sys.system_id].system_pointer;
+        return cast(Sys*) systems[Sys.system_id].system_pointer;
     }
 
     void registerComponent(Comp)()
@@ -513,6 +513,7 @@ class EntityManager
     private void __removeComponents(EntityID entity_id, ushort[] del_ids)
     {
         Entity* entity = id_manager.getEntityPointer(entity_id);
+        if(!entity)return;
         EntitiesBlock* block = getMetaData(entity);
         EntityInfo* info = block.type_data;
 
@@ -583,6 +584,7 @@ class EntityManager
     {
         uint num = cast(uint) new_ids.length;
         Entity* entity = id_manager.getEntityPointer(entity_id);
+        if(!entity)return;
         EntitiesBlock* block = getMetaData(entity);
         EntityInfo* info = block.type_data;
         ushort[] ids = (cast(ushort*) alloca(ushort.sizeof * (info.components.length + num)))[0
@@ -774,6 +776,7 @@ class EntityManager
                 else
                 {
                     previous_block.next_block = block;
+                    block.prev_block = previous_block;
                     block.id = previous_block.id + 1;
                 }
                 info.first_with_free_space = block;
@@ -837,6 +840,28 @@ class EntityManager
             }
         }
 
+        if (block.entities_count == 0)
+        {
+            if (block.type_data.first_block is block)
+            {
+                block.type_data.first_block = block.next_block;
+            }
+            if (block.type_data.first_with_free_space is block)
+            {
+                block.type_data.first_with_free_space = block.next_block;//block.type_data.first_block;
+            }
+            if (block.prev_block)
+            {
+                block.prev_block.next_block = block.next_block;
+            }
+            if(block.next_block)
+            {
+                block.next_block.prev_block = block.prev_block;
+            }
+            allocator.freeBlock(block);
+            return;
+        }
+
         if (pos == block.entities_count)
             return;
 
@@ -922,8 +947,8 @@ class EntityManager
     export void begin()
     {
         updateBlocks();
-        changeEntites();
         removeEntities();
+        changeEntites();
         foreach (ref system; instance.systems)
         {
             if (system.m_begin)
@@ -939,8 +964,8 @@ class EntityManager
                 system.m_end(system.m_system_pointer);
         }
         updateBlocks();
-        changeEntites();
         removeEntities();
+        changeEntites();
 
         clearEvents();
     }
@@ -1003,15 +1028,17 @@ class EntityManager
         }
 
         ///pointer to Entity type info
-        EntityInfo* type_data;
+        EntityInfo* type_data = null;
         ///number of entities in block
-        ushort entities_count;
+        ushort entities_count = 0;
         ///number of new entities in block
-        ushort added_count;
+        ushort added_count = 0;
         ///block id
-        uint id;
+        uint id = 0;
         ///pointer to next block/page
-        EntitiesBlock* next_block;
+        EntitiesBlock* next_block = null;
+        ///pointer to next block/page
+        EntitiesBlock* prev_block = null;
         //there is a loooot of data (4kB, pure magic)
     }
 
diff --git a/tests/tests.d b/tests/tests.d
index 8c778d7..c4840ba 100644
--- a/tests/tests.d
+++ b/tests/tests.d
@@ -93,6 +93,7 @@ int main()
 
 	struct TestSystem
 	{
+		__gshared ushort system_id;
 
 		void onCreate()
 		{
@@ -152,6 +153,7 @@ int main()
 
 	struct TestSystemWithHighPriority
 	{
+		__gshared ushort system_id;
 
 		void initialize(ref Entity entity, ref TestComp comp)
 		{
@@ -173,6 +175,7 @@ int main()
 
 	struct TestSystem2
 	{
+		__gshared ushort system_id;
 
 		void onEnable()
 		{