The 2.7 branch and HEAD have been changed so that they require databases to be present in the config file to start properly. Previous 2.7 betas did not require this; in fact, there were no databases specified in the default zope.conf file, and Zope guessed at what the defaults were. Since guessing this way is bad, I've changed it to require explicit database statements in the config. To ensure that your 2.7 or HEAD checkouts start properly, place the following in your config file (or just uncomment it from the default config file): <zodb_db main> # Main FileStorage database <filestorage> path $INSTANCE/var/Data.fs </filestorage> mount-point / </zodb_db> <zodb_db temporary> # Temporary storage database (for sessions) <temporarystorage> name temporary storage for sessioning </temporarystorage> mount-point /temp_folder container-class Products.TemporaryFolder.TemporaryContainer </zodb_db>