handle error and update modal window msg

supervisely/train/src/sly_train.py

@@ -40,7 +40,15 @@ def train(api: sly.Api, task_id, context, state, app_logger):
 
         # download and preprocess Sypervisely project (using cache)
         download_progress = get_progress_cb("Download data (using cache)", g.project_info.items_count * 2)
-        sly.download_project(api, project_id, project_dir, cache=my_app.cache, progress_cb=download_progress)
+        try:
+            sly.download_project(api, project_id, project_dir, cache=my_app.cache, progress_cb=download_progress)
+        except Exception as e:
+            sly.logger.warn("Can not download project")
+            raise Exception(
+                "Can not download the project. "
+                f"Check if the project is available, it is not archived, not modified and not empty. "
+                f"{repr(e)}"
+            )
 
         # preprocessing: transform labels to bboxes, filter classes, ...
         try:
@@ -120,7 +128,7 @@ def train(api: sly.Api, task_id, context, state, app_logger):
         upload_artifacts(g.local_artifacts_dir, g.remote_artifacts_dir)
         set_task_output()
     except Exception as e:
-        my_app.show_modal_window(f"Something went wrong. Find more info in the app logs. Error: {str(e)}", level="error")
+        my_app.show_modal_window(f"Something went wrong. Find more info in the app logs. {repr(e)}", level="error")
         api.app.set_field(task_id, "state.started", False)
 
     # stop application