When updating FotoWeb to a newer build, the upgrade wizard hangs forever at the point where it tries to start MongoDB
This happens when the MongoDB host is set to the server's actual host name rather than localhost.
When FotoWeb runs using its own bundled MongoDB instance, the MongoDB server MUST be set to localhost. Otherwise FotoWeb will assume that it has been configured to use an external MongoDB instance and is then no longer responsible for starting and stopping the MongoDB instance itself.
Unless you have configured an external MongoDB instance or a replica set, make sure FotoWeb has been configured to connect to MongoDB on localhost, not the local host's name explicitly.