diff --git a/core/object.cpp b/core/object.cpp
index 316c6242682..525eb2ff385 100644
--- a/core/object.cpp
+++ b/core/object.cpp
@@ -1182,10 +1182,10 @@ Variant Object::_emit_signal(const Variant **p_args, int p_argcount, Variant::Ca
 	return Variant();
 }
 
-void Object::emit_signal(const StringName &p_name, const Variant **p_args, int p_argcount) {
+Error Object::emit_signal(const StringName &p_name, const Variant **p_args, int p_argcount) {
 
 	if (_block_signals)
-		return; //no emit, signals blocked
+		return ERR_CANT_AQUIRE_RESOURCE; //no emit, signals blocked
 
 	Signal *s = signal_map.getptr(p_name);
 	if (!s) {
@@ -1194,11 +1194,11 @@ void Object::emit_signal(const StringName &p_name, const Variant **p_args, int p
 		//check in script
 		if (!signal_is_valid && !script.is_null() && !Ref<Script>(script)->has_script_signal(p_name)) {
 			ERR_EXPLAIN("Can't emit non-existing signal " + String("\"") + p_name + "\".");
-			ERR_FAIL();
+			ERR_FAIL_V(ERR_UNAVAILABLE);
 		}
 #endif
 		//not connected? just return
-		return;
+		return ERR_UNAVAILABLE;
 	}
 
 	List<_ObjectSignalDisconnectData> disconnect_data;
@@ -1214,6 +1214,8 @@ void Object::emit_signal(const StringName &p_name, const Variant **p_args, int p
 
 	Vector<const Variant *> bind_mem;
 
+	Error err = OK;
+
 	for (int i = 0; i < ssize; i++) {
 
 		const Connection &c = slot_map.getv(i).conn;
@@ -1249,12 +1251,14 @@ void Object::emit_signal(const StringName &p_name, const Variant **p_args, int p
 		} else {
 			Variant::CallError ce;
 			target->call(c.method, args, argc, ce);
+
 			if (ce.error != Variant::CallError::CALL_OK) {
 
 				if (ce.error == Variant::CallError::CALL_ERROR_INVALID_METHOD && !ClassDB::class_exists(target->get_class_name())) {
 					//most likely object is not initialized yet, do not throw error.
 				} else {
 					ERR_PRINTS("Error calling method from signal '" + String(p_name) + "': " + Variant::get_call_error_text(target, c.method, args, argc, ce));
+					err = ERR_METHOD_NOT_FOUND;
 				}
 			}
 		}
@@ -1274,21 +1278,24 @@ void Object::emit_signal(const StringName &p_name, const Variant **p_args, int p
 		disconnect(dd.signal, dd.target, dd.method);
 		disconnect_data.pop_front();
 	}
+
+	return err;
 }
 
-void Object::emit_signal(const StringName &p_name, VARIANT_ARG_DECLARE) {
+Error Object::emit_signal(const StringName &p_name, VARIANT_ARG_DECLARE) {
 
 	VARIANT_ARGPTRS;
 
 	int argc = 0;
 
 	for (int i = 0; i < VARIANT_ARG_MAX; i++) {
+
 		if (argptr[i]->get_type() == Variant::NIL)
 			break;
 		argc++;
 	}
 
-	emit_signal(p_name, argptr, argc);
+	return emit_signal(p_name, argptr, argc);
 }
 
 void Object::_add_user_signal(const String &p_name, const Array &p_args) {
diff --git a/core/object.h b/core/object.h
index 148a73fbc4d..ca2090094ee 100644
--- a/core/object.h
+++ b/core/object.h
@@ -654,8 +654,8 @@ public:
 	void set_script_and_instance(const RefPtr &p_script, ScriptInstance *p_instance); //some script languages can't control instance creation, so this function eases the process
 
 	void add_user_signal(const MethodInfo &p_signal);
-	void emit_signal(const StringName &p_name, VARIANT_ARG_LIST);
-	void emit_signal(const StringName &p_name, const Variant **p_args, int p_argcount);
+	Error emit_signal(const StringName &p_name, VARIANT_ARG_LIST);
+	Error emit_signal(const StringName &p_name, const Variant **p_args, int p_argcount);
 	void get_signal_list(List<MethodInfo> *p_signals) const;
 	void get_signal_connection_list(const StringName &p_signal, List<Connection> *p_connections) const;
 	void get_all_signal_connections(List<Connection> *p_connections) const;
diff --git a/core/resource.cpp b/core/resource.cpp
index 5625784396e..86069bf2e90 100644
--- a/core/resource.cpp
+++ b/core/resource.cpp
@@ -32,6 +32,7 @@
 #include "core_string_names.h"
 #include "io/resource_loader.h"
 #include "os/file_access.h"
+#include "scene/main/node.h" //only so casting works
 #include "script_language.h"
 #include <stdio.h>
 
diff --git a/core/variant.h b/core/variant.h
index 583a0d09a0d..4d137efac21 100644
--- a/core/variant.h
+++ b/core/variant.h
@@ -42,8 +42,8 @@
 #include "io/ip_address.h"
 #include "math_2d.h"
 #include "matrix3.h"
-#include "os/power.h"
 #include "node_path.h"
+#include "os/power.h"
 #include "plane.h"
 #include "quat.h"
 #include "rect3.h"
@@ -239,7 +239,7 @@ public:
 
 	operator IP_Address() const;
 
-	Variant(bool p_bool);
+	explicit Variant(bool p_bool);
 	Variant(signed int p_int); // real one
 	Variant(unsigned int p_int);
 #ifdef NEED_LONG_INT
diff --git a/scene/3d/visibility_notifier.cpp b/scene/3d/visibility_notifier.cpp
index 5e6561adb74..cc81a4cb569 100644
--- a/scene/3d/visibility_notifier.cpp
+++ b/scene/3d/visibility_notifier.cpp
@@ -29,6 +29,7 @@
 /*************************************************************************/
 #include "visibility_notifier.h"
 
+#include "scene/3d/camera.h"
 #include "scene/3d/physics_body.h"
 #include "scene/animation/animation_player.h"
 #include "scene/scene_string_names.h"
@@ -42,6 +43,7 @@ void VisibilityNotifier::_enter_camera(Camera *p_camera) {
 		emit_signal(SceneStringNames::get_singleton()->screen_entered);
 		_screen_enter();
 	}
+
 	emit_signal(SceneStringNames::get_singleton()->camera_entered, p_camera);
 }