Fixed – Could not find an implementation of the query pattern for source type. ‘Where’ not found (LINQ, Dataverse)

While working on a LINQ query using early-bound classes in a Dynamics 365 plugin, we encountered a familiar error.

“Could not find an implementation of the query pattern for source type. ‘Where’ not found”

At a glance, everything looked fine. The query was syntactically correct, and the early-bound class was generated properly.

After spending some time, we realized that the error message wasn’t due to the query or the early-bound class itself. It was because we forgot to include the following directive:

using System.Linq;

Without this, C# doesn’t recognize LINQ query methods like Where, Select, or ToList.

Adding this single line at the top of the file resolved the issue immediately, the LINQ query compiled and executed as expected.

Hope it helps..