diff --git a/neode-ui/mock-backend.js b/neode-ui/mock-backend.js
index 08e0eb8c..7a58d883 100755
--- a/neode-ui/mock-backend.js
+++ b/neode-ui/mock-backend.js
@@ -40,7 +40,13 @@ const corsOptions = {
 }
 
 app.use(cors(corsOptions))
-app.use(express.json({ limit: '50mb' }))
+// Skip JSON body parsing for filebrowser upload routes (binary file bodies)
+app.use((req, res, next) => {
+  if (req.path.startsWith('/app/filebrowser/api/resources') && req.method === 'POST') {
+    return next()
+  }
+  express.json({ limit: '50mb' })(req, res, next)
+})
 app.use(cookieParser())
 
 // Mock session storage