diff --git a/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AnimationFileModel.kt b/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AnimationFileModel.kt
index 005c784..53f496e 100644
--- a/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AnimationFileModel.kt
+++ b/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AnimationFileModel.kt
@@ -1,5 +1,7 @@
 package com.rhubarb_lip_sync.rhubarb_for_spine
 
+import javafx.beans.binding.BooleanBinding
+import javafx.beans.property.SimpleBooleanProperty
 import javafx.beans.property.SimpleListProperty
 import javafx.beans.property.SimpleObjectProperty
 import javafx.beans.property.SimpleStringProperty
@@ -57,6 +59,21 @@ class AnimationFileModel(animationFilePath: Path, private val executor: Executor
 			}
 			.observable()
 	)
+	val audioFileModels by audioFileModelsProperty
+
+	val busyProperty = SimpleBooleanProperty().apply {
+		bind(object : BooleanBinding() {
+			init {
+				for (audioFileModel in audioFileModels) {
+					super.bind(audioFileModel.busyProperty)
+				}
+			}
+			override fun computeValue(): Boolean {
+				return audioFileModels.any { it.busy }
+			}
+		})
+	}
+	val busy by busyProperty
 
 	private fun saveAnimation(mouthCues: List<MouthCue>, audioEventName: String) {
 		val animationName = getAnimationName(audioEventName)
@@ -66,8 +83,6 @@ class AnimationFileModel(animationFilePath: Path, private val executor: Executor
 
 	private fun getAnimationName(audioEventName: String): String = "say_$audioEventName"
 
-	val audioFileModels by audioFileModelsProperty
-
 	init {
 		slots = spineJson.slots.observable()
 		mouthSlot = spineJson.guessMouthSlot()
diff --git a/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AudioFileModel.kt b/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AudioFileModel.kt
index fb4b66e..0bf6076 100644
--- a/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AudioFileModel.kt
+++ b/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/AudioFileModel.kt
@@ -1,6 +1,7 @@
 package com.rhubarb_lip_sync.rhubarb_for_spine
 
 import javafx.application.Platform
+import javafx.beans.binding.BooleanBinding
 import javafx.beans.binding.ObjectBinding
 import javafx.beans.binding.StringBinding
 import javafx.beans.property.SimpleBooleanProperty
@@ -66,6 +67,19 @@ class AudioFileModel(
 	}
 	private val audioFileState by audioFileStateProperty
 
+	val busyProperty = SimpleBooleanProperty().apply {
+		bind(object : BooleanBinding() {
+			init {
+				super.bind(futureProperty)
+			}
+			override fun computeValue(): Boolean {
+				return future != null
+			}
+
+		})
+	}
+	val busy by busyProperty
+
 	val statusLabelProperty = SimpleStringProperty().apply {
 		bind(object : StringBinding() {
 			init {
diff --git a/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/MainView.kt b/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/MainView.kt
index f43822f..76a0823 100644
--- a/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/MainView.kt
+++ b/extras/rhubarb-for-spine/src/main/kotlin/com/rhubarb_lip_sync/rhubarb_for_spine/MainView.kt
@@ -35,6 +35,7 @@ class MainView : View() {
 		minWidth = 800.0
 		prefWidth = 1000.0
 		fieldset("Settings") {
+			disableProperty().bind(fileModelProperty.select { it!!.busyProperty })
 			field("Spine JSON file") {
 				filePathTextField = textfield {
 					textProperty().bindBidirectional(mainModel.filePathStringProperty)
@@ -123,13 +124,13 @@ class MainView : View() {
 		}
 
 		onDragOver = EventHandler<DragEvent> { event ->
-			if (event.dragboard.hasFiles()) {
+			if (event.dragboard.hasFiles() && mainModel.animationFileModel?.busy != true) {
 				event.acceptTransferModes(TransferMode.COPY)
 				event.consume()
 			}
 		}
 		onDragDropped = EventHandler<DragEvent> { event ->
-			if (event.dragboard.hasFiles()) {
+			if (event.dragboard.hasFiles() && mainModel.animationFileModel?.busy != true) {
 				filePathTextField!!.text = event.dragboard.files.firstOrNull()?.path
 				event.isDropCompleted = true
 				event.consume()