Fix

src/gen.py

@@ -2715,7 +2715,7 @@ def evaluate(
                             res = job.communicator.job.outputs[-1]
                             res_dict = ast.literal_eval(res)
                             text = res_dict['response']
-                            sources = res_dict['sources']
+                            sources = res_dict.get('sources', '')
                             if gr_prompt_type == 'plain':
                                 # then gradio server passes back full prompt + text
                                 prompt_and_text = text
@@ -2736,7 +2736,7 @@ def evaluate(
                         res = res_all[-1]
                         res_dict = ast.literal_eval(res)
                         text = res_dict['response']
-                        sources = res_dict['sources']
+                        sources = res_dict.get('sources', '')
                     else:
                         # go with old text if last call didn't work
                         e = job.future._exception