Richard, by default GAE dev_appserver saves the datastore in temp by default. this will tend to get deleted by the OS. I run my dev_appserver with the --datastore_path parameter and pointing to a spot where i can be sure the file is not deleted.
check that your index.yaml starts like: indexes: # AUTOGENERATED # This index.yaml is automatically updated whenever the dev_appserver # detects that a new type of query is run. If you want to manage the # index.yaml file manually, remove the above marker line (the line # saying "# AUTOGENERATED"). If you want to manage some indexes # manually, move them above the marker line. The index.yaml file is # automatically uploaded to the admin console when you next deploy # your application using appcfg.py. if not GAE gets confused and does not update the index.yaml file. you might get it to work just be deleting the index.yaml file and seeing if GAE re-creates it. good luck! once it is working it is quite nice. cfh
