fix: DEV-3317: Fix empty model error in get_or_create (#179)

label_studio_ml/model.py

@@ -108,7 +108,8 @@ def get_result_from_job_id(self, job_id):
         DON'T OVERRIDE THIS FUNCTION! Instead, override _get_result_from_job_id
         """
         result = self._get_result_from_job_id(job_id)
-        assert isinstance(result, dict)
+        assert isinstance(result, dict), f"Job {job_id} was finished unsuccessfully. No result was saved in job folder." \
+                                         f"Please clean up failed job folders to remove this error from log."
         result['job_id'] = job_id
         return result
 
@@ -486,10 +487,12 @@ def create(cls, project=None, label_config=None, train_output=None, version=None
     def get_or_create(
         cls, project=None, label_config=None, force_reload=False, train_output=None, version=None, **kwargs
     ):
+        m = cls.get(project)
         # reload new model if model is not loaded into memory OR force_reload=True OR model versions are mismatched
         if not cls.has_active_model(project) or \
                 force_reload or \
-                (cls.get(project).model_version != version and version is not None):  # noqa
+                m is not None or \
+                (m.model_version != version and version is not None):  # noqa
             logger.debug('Reload model for project={project} with version={version}'.format(
                 project=project, version=version))
             cls.create(project, label_config, train_output, version, **kwargs)