diff --git a/scene/2d/tile_map.cpp b/scene/2d/tile_map.cpp
index ed07d5d11ec..6fcbf541c6b 100644
--- a/scene/2d/tile_map.cpp
+++ b/scene/2d/tile_map.cpp
@@ -2839,7 +2839,7 @@ void TileMap::_set_tile_data(int p_layer, const Vector<int> &p_data) {
 	const int *r = p_data.ptr();
 
 	int offset = (format >= FORMAT_2) ? 3 : 2;
-	ERR_FAIL_COND_MSG(c % offset != 0, "Corrupted tile data.");
+	ERR_FAIL_COND_MSG(c % offset != 0, vformat("Corrupted tile data. Got size: %s. Expected modulo: %s", offset));
 
 	clear_layer(p_layer);
 
diff --git a/scene/2d/tile_map.h b/scene/2d/tile_map.h
index d187a917b5f..cf62237a3ec 100644
--- a/scene/2d/tile_map.h
+++ b/scene/2d/tile_map.h
@@ -179,7 +179,7 @@ private:
 		FORMAT_2,
 		FORMAT_3
 	};
-	mutable DataFormat format = FORMAT_1; // Assume lowest possible format if none is present;
+	mutable DataFormat format = FORMAT_3;
 
 	static constexpr float FP_ADJUST = 0.00001;