glTF: Better error handling when image is not found

scripts/addons_core/io_scene_gltf2/__init__.py

@@ -5,7 +5,7 @@
 bl_info = {
     'name': 'glTF 2.0 format',
     'author': 'Julien Duroure, Scurest, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
-    "version": (4, 5, 25),
+    "version": (4, 5, 26),
     'blender': (4, 4, 0),
     'location': 'File > Import-Export',
     'description': 'Import-Export as glTF 2.0',

scripts/addons_core/io_scene_gltf2/blender/exp/material/encode_image.py

@@ -413,6 +413,7 @@ class ExportImage:
             return _encode_temp_image(tmp_image, self.file_format, export_settings)
 
     def __encode_from_image_tile(self, udim_image, tile, export_settings):
+        data = None
         src_path = bpy.path.abspath(udim_image.filepath_raw).replace("<UDIM>", tile)
 
         if os.path.isfile(src_path):
@@ -433,6 +434,7 @@ class ExportImage:
         # We don't manage UDIM packed image, so this could not happen to be here
         # Lets display an error
         export_settings['log'].error("UDIM packed images are not supported for export. Please unpack them before exporting.")
+        return b''
 
 
 def _encode_temp_image(tmp_image: bpy.types.Image, file_format: str, export_settings) -> bytes: