This may sound a bit strange, but I had to downgrade Episerver Find in lower environments. It is not enough to install the old NuGet library into your development environment and publish it again to Integration. First, you need to make sure that the database has not been upgraded, but if it was, you should open a ticket to the Epi support team and ask them to restore an old copy of the database. Then, and the most important step, you must delete the distribution folder from your local environment at this path /obj/Integration to avoid conflicts with library versions. Also, use the Remove additional files at destination option found in the Visual Studio deployment wizard. That’s it, now deploy again to Integration and things will be as before.