Post-release fixes.

build/three.js

@@ -21886,6 +21886,7 @@
 
 			if ( isAnimating ) return;
 			( vr.getDevice() || window ).requestAnimationFrame( loop );
+			isAnimating = true;
 
 		}
 
@@ -43341,7 +43342,7 @@
 			set: function ( value ) {
 
 				console.warn( 'THREE.' + this.type + ': .shading has been removed. Use the boolean .flatShading instead.' );
-				this.flatShading = ( value === THREE.FlatShading ) ? true : false;
+				this.flatShading = ( value === FlatShading );
 
 			}
 		}

build/three.module.js

@@ -21880,6 +21880,7 @@ function WebGLRenderer( parameters ) {
 
 		if ( isAnimating ) return;
 		( vr.getDevice() || window ).requestAnimationFrame( loop );
+		isAnimating = true;
 
 	}
 
@@ -43335,7 +43336,7 @@ Object.defineProperties( Material.prototype, {
 		set: function ( value ) {
 
 			console.warn( 'THREE.' + this.type + ': .shading has been removed. Use the boolean .flatShading instead.' );
-			this.flatShading = ( value === THREE.FlatShading ) ? true : false;
+			this.flatShading = ( value === FlatShading );
 
 		}
 	}

editor/js/Sidebar.Material.js

@@ -26,8 +26,8 @@ Sidebar.Material = function ( editor ) {
 
 	materialSlotRow.add( new UI.Text( 'Slot' ).setWidth( '90px' ) );
 
-	var materialSlotSelect =  new UI.Select().setWidth( '170px' ).setFontSize( '12px' ).onChange( update );
-
+	var materialSlotSelect = new UI.Select().setWidth( '170px' ).setFontSize( '12px' ).onChange( update );
+	materialSlotSelect.setOptions( { 0: '' } ).setValue( 0 );
 	materialSlotRow.add( materialSlotSelect );
 
 	container.add( materialSlotRow );
@@ -518,7 +518,7 @@ Sidebar.Material = function ( editor ) {
 
 		if ( currentMaterialSlot !== previousSelectedSlot ) refreshUI( true );
 
-		material  = editor.getObjectMaterial( currentObject, currentMaterialSlot )
+		material = editor.getObjectMaterial( currentObject, currentMaterialSlot )
 
 		var textureWarning = false;
 		var objectHasUvs = false;