This patch (https://github.com/doctrine/dbal/commit/fabe3c346b24dcb70eba0cb3936998ec6cc152f0) introduced a bug where the schemaNeedsCreation method always returns true if the schema name isn't 'default' or 'public'.
We heavily use schema's in our application and whenever an insert query is queued, it fails because the schema in question already exists but the platform adapter fails to detect that and continues with a "CREATE SCHEMA" query which fails.
The easy fix is to add the 'IF NOT EXISTS' clause to the 'CREATE SCHEMA' query but that will only function on Postgresql 9.3 and upward since 'IF NOT EXISTS' wasn't possible in earlier versions for schema creation.
Beter would be to load the existing schema's and compare them to those. I would create a pull request but i'm not sure how to obtain a database connection in the Platform (if at all possible) to pull a list of already known schema's?