diff --git a/rts/Sim/Projectiles/ExpGenSpawner.cpp b/rts/Sim/Projectiles/ExpGenSpawner.cpp
index ee2683ddc6e..712afe02caf 100644
--- a/rts/Sim/Projectiles/ExpGenSpawner.cpp
+++ b/rts/Sim/Projectiles/ExpGenSpawner.cpp
@@ -17,11 +17,7 @@ CR_REG_METADATA(CExpGenSpawner,
 ))
 
 
-CExpGenSpawner::CExpGenSpawner() :
-	CProjectile(),
-	delay(1),
-	damage(0.0f),
-	explosionGenerator(nullptr)
+CExpGenSpawner::CExpGenSpawner() : CProjectile()
 {
 	checkCol = false;
 	deleteMe = false;
@@ -29,26 +25,26 @@ CExpGenSpawner::CExpGenSpawner() :
 
 void CExpGenSpawner::Serialize(creg::ISerializer* s) {
 	int generatorID;
+
 	if (s->IsWriting())
 		generatorID = explosionGenerator->GetGeneratorID();
 
 	s->SerializeInt(&generatorID, sizeof(generatorID));
 
-	if (!s->IsWriting())
-		explosionGenerator = explGenHandler.GetGenerator(generatorID);
-}
+	if (s->IsWriting())
+		return;
 
-void CExpGenSpawner::Update()
-{
-	if ((deleteMe |= ((delay--) <= 0))) {
-		explosionGenerator->Explosion(pos, dir, damage, 0.0f, 0.0f, owner(), nullptr);
-	}
+	// NOTE:
+	//   projectiles are serialized, but ExplosionGeneratorHandler itself is not
+	//   as such generator-id can be invalid when this spawner gets deserialized
+	//   (if additional generators were loaded at runtime before game was saved)
+	explosionGenerator = explGenHandler.GetGenerator(generatorID);
 }
 
-
-int CExpGenSpawner::GetProjectilesCount() const
+void CExpGenSpawner::Update()
 {
-	return 0;
+	if ((deleteMe |= ((delay--) <= 0)))
+		explosionGenerator->Explosion(pos, dir,  damage, 0.0f, 0.0f,  owner(), nullptr);
 }
 
 
@@ -59,6 +55,7 @@ bool CExpGenSpawner::GetMemberInfo(SExpGenSpawnableMemberInfo& memberInfo)
 
 	CHECK_MEMBER_INFO_INT  (CExpGenSpawner, delay )
 	CHECK_MEMBER_INFO_FLOAT(CExpGenSpawner, damage)
+	// TODO: much nicer to load cegID directly via LoadGeneratorID callback
 	CHECK_MEMBER_INFO_PTR  (CExpGenSpawner, explosionGenerator, explGenHandler.LoadGenerator)
 
 	return false;
diff --git a/rts/Sim/Projectiles/ExpGenSpawner.h b/rts/Sim/Projectiles/ExpGenSpawner.h
index 22d77174b40..fb7e2c4a1b3 100644
--- a/rts/Sim/Projectiles/ExpGenSpawner.h
+++ b/rts/Sim/Projectiles/ExpGenSpawner.h
@@ -18,15 +18,15 @@ class CExpGenSpawner : public CProjectile
 
 	virtual void Update() override;
 
-	virtual int GetProjectilesCount() const override;
+	virtual int GetProjectilesCount() const override { return 0; }
 
 	static bool GetMemberInfo(SExpGenSpawnableMemberInfo& memberInfo);
 
 private:
-	int delay;
-	float damage;
+	int delay = 1;
+	float damage = 0.0f;
 
-	IExplosionGenerator* explosionGenerator;
+	IExplosionGenerator* explosionGenerator = nullptr;
 };
 
 #endif // EXP_GEN_SPAWNER_H
diff --git a/rts/Sim/Projectiles/ExplosionGenerator.cpp b/rts/Sim/Projectiles/ExplosionGenerator.cpp
index a27c3fb2262..42d7b2b308c 100644
--- a/rts/Sim/Projectiles/ExplosionGenerator.cpp
+++ b/rts/Sim/Projectiles/ExplosionGenerator.cpp
@@ -154,11 +154,15 @@ std::string ClassAliasList::FindAlias(const std::string& className) const
 void CExplosionGeneratorHandler::Init()
 {
 	egMemPool.clear();
-	egMemPool.reserve(32);
+	egMemPool.reserve(512);
+
+	explosionGenerators.reserve(512);
+	explosionGenerators.push_back(egMemPool.alloc<CStdExplosionGenerator>()); // id=0 (shared standard EG)
+	explosionGenerators.push_back(egMemPool.alloc<   IExplosionGenerator>()); // id=1 (dummy fallback EG)
+
+	explosionGenerators[EXPGEN_ID_STANDARD]->SetGeneratorID(EXPGEN_ID_STANDARD);
+	explosionGenerators[EXPGEN_ID_FALLBACK]->SetGeneratorID(EXPGEN_ID_FALLBACK);
 
-	explosionGenerators.reserve(32);
-	explosionGenerators.push_back(egMemPool.alloc<CStdExplosionGenerator>()); // id=0
-	explosionGenerators[0]->SetGeneratorID(EXPGEN_ID_STANDARD);
 
 	exploParser = nullptr;
 	aliasParser = nullptr;
@@ -331,8 +335,9 @@ IExplosionGenerator* CExplosionGeneratorHandler::GetGenerator(unsigned int expGe
 {
 	if (expGenID == EXPGEN_ID_INVALID)
 		return nullptr;
+	// can happen after save/load for spawners
 	if (expGenID >= explosionGenerators.size())
-		return nullptr;
+		return explosionGenerators[EXPGEN_ID_FALLBACK];
 
 	return explosionGenerators[expGenID];
 }
diff --git a/rts/Sim/Projectiles/ExplosionGenerator.h b/rts/Sim/Projectiles/ExplosionGenerator.h
index 27c34c0d4eb..af88c70cd4f 100644
--- a/rts/Sim/Projectiles/ExplosionGenerator.h
+++ b/rts/Sim/Projectiles/ExplosionGenerator.h
@@ -42,6 +42,7 @@ class CExplosionGeneratorHandler
 	enum {
 		EXPGEN_ID_INVALID  = -1u,
 		EXPGEN_ID_STANDARD =  0u,
+		EXPGEN_ID_FALLBACK =  1u,
 	};
 
 	void Init();
@@ -93,7 +94,7 @@ class IExplosionGenerator
 	IExplosionGenerator(): generatorID(CExplosionGeneratorHandler::EXPGEN_ID_INVALID) {}
 	virtual ~IExplosionGenerator() {}
 
-	virtual bool Load(CExplosionGeneratorHandler* handler, const char* tag) = 0;
+	virtual bool Load(CExplosionGeneratorHandler* handler, const char* tag) { return false; }
 	virtual bool Reload(CExplosionGeneratorHandler* handler, const char* tag) { return true; }
 	virtual bool Explosion(
 		const float3& pos,
@@ -103,7 +104,7 @@ class IExplosionGenerator
 		float gfxMod,
 		CUnit* owner,
 		CUnit* hit
-	) = 0;
+	) { return false; }
 
 	unsigned int GetGeneratorID() const { return generatorID; }
 	void SetGeneratorID(unsigned int id) { generatorID = id; }