diff --git a/.circleci/config.yml b/.circleci/config.yml
index 4af55df56..3b38b6db2 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -426,7 +426,7 @@ jobs:
   test-dui-3:
     docker:
       - image: cimg/node:18.16.0
-    resource_class: medium
+    resource_class: medium+
     steps:
       - checkout
       - restore_cache:
diff --git a/packages/viewer/src/modules/Viewer.ts b/packages/viewer/src/modules/Viewer.ts
index 85af02395..2dc3334c8 100644
--- a/packages/viewer/src/modules/Viewer.ts
+++ b/packages/viewer/src/modules/Viewer.ts
@@ -462,20 +462,14 @@ export class Viewer extends EventEmitter implements IViewer {
     token: string = null,
     enableCaching = true
   ) {
-    try {
-      if (++this.inProgressOperations === 1)
-        (this as EventEmitter).emit(ViewerEvent.Busy, true)
-
-      const loader = new ViewerObjectLoader(this, url, token, enableCaching)
-      this.loaders[url] = loader
-      await loader.load()
-    } finally {
-      if (--this.inProgressOperations === 0)
-        (this as EventEmitter).emit(ViewerEvent.Busy, false)
-    }
+    const loader = new ViewerObjectLoader(this, url, token, enableCaching)
+    this.loaders[url] = loader
+    await loader.load()
   }
 
   public async loadObject(url: string, token: string = null, enableCaching = true) {
+    if (++this.inProgressOperations === 1)
+      (this as EventEmitter).emit(ViewerEvent.Busy, true)
     await this.downloadObject(url, token, enableCaching)
 
     let t0 = performance.now()
@@ -491,6 +485,8 @@ export class Viewer extends EventEmitter implements IViewer {
     this.emit(ViewerEvent.LoadComplete, url)
     this.loaders[url].dispose()
     delete this.loaders[url]
+    if (--this.inProgressOperations === 0)
+      (this as EventEmitter).emit(ViewerEvent.Busy, false)
   }
 
   public async loadObjectAsync(
@@ -499,6 +495,8 @@ export class Viewer extends EventEmitter implements IViewer {
     enableCaching = true,
     priority = 1
   ) {
+    if (++this.inProgressOperations === 1)
+      (this as EventEmitter).emit(ViewerEvent.Busy, true)
     await this.downloadObject(url, token, enableCaching)
 
     let t0 = performance.now()
@@ -514,6 +512,8 @@ export class Viewer extends EventEmitter implements IViewer {
     }
     this.loaders[url].dispose()
     delete this.loaders[url]
+    if (--this.inProgressOperations === 0)
+      (this as EventEmitter).emit(ViewerEvent.Busy, false)
   }
 
   public async cancelLoad(url: string, unload = false) {
@@ -522,8 +522,10 @@ export class Viewer extends EventEmitter implements IViewer {
     this.speckleRenderer.cancelRenderTree(url)
     if (unload) {
       await this.unloadObject(url)
+    } else {
+      if (--this.inProgressOperations === 0)
+        (this as EventEmitter).emit(ViewerEvent.Busy, false)
     }
-    return
   }
 
   public async unloadObject(url: string) {