visual studio 2015 update 1 Oracle ADO.NET provider is either not registered, or could not be loaded

Using Visual Studio 2015, the Framework version 4.6, Entity Framework 6, and the Oracle Database, I'm creating an application. Until today, everything was operating as it should after installing Visual Studio 2015 Update 1. The application couldn't be built, and I'm receiving the following error message:

ADO.NET provider with invariant name 'Oracle.ManagedDataAccess.Client' is either not registered in the machine or application config file, or could not be loaded.

Without success, I tried recovering packages, uninstalling and re-adding the Oracle packages (DataAccess and EntitFrameWork). I discovered a slightly related problem in the Oracle community, but the individual had to reinstall Visual Studio to fix it.