Update ASSIMP Viewer

Author: GitHubDragonFly

viewers/templates/ASSIMP Viewer.html

@@ -3708,6 +3708,11 @@
       function loadFile() {
         let lfile = local_files ? local_files[ selected_gltf_file ] : ( assimp_load === true ? selected_gltf_file : null );
 
+        if (lfile === null) {
+          handle_error( 'No valid file selected!' );
+          return;
+        }
+
         gltf_loader.load( URL.createObjectURL( lfile ), async function( gltf ) {
           URL.revokeObjectURL( assimp_load === true ? selected_gltf_file : lfile );
 
@@ -4061,7 +4066,7 @@
               handle_error( error );
             });
           } else {
-            gltf_loader.load( selected_gltf_url_file ? selected_gltf_url_file : selected_gltf_file, async function( gltf ) {
+            gltf_loader.load( selected_gltf_url_file, async function( gltf ) {
               parser = gltf.parser;
               scenes = gltf.scenes;
               cameras = gltf.cameras;