Intermittent Task Failure BAD_REQUEST: POST to pipeline that does not have an unlinked input view

This pipeline is executed by a [Scheduled Task > Pipeline > HTTP Client > Triggered Task] regularly. This pipeline hasn't changed structure in months. Occasionally I will get an error that the Triggered Task failed with the error: 

Reason: HTTP Code: HTTPStatus.BAD_REQUEST Status: POST to pipeline that does not have an unlinked input view Errors: None

Any ideas why the task occasionally acts like the pipeline has a different structure? I can't replicate the error after it occurs, but it hasn't occurred intermittently for months.