w3wp.exe: All query processing components are in ‘Failed’ status.

Today, we received from our customer the information about some errors to use the search in a SharePoint website, following the error: In URL log, we saw the following two errors, Unexpected and Critical respectively: 1 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Microsoft.Ceres.InteractionEngine.Component.FlowHandleRegistry : Exceptions occurred when evaluating the flow. Microsoft.Ceres.Evaluation.DataModel.EvaluationException: Cannot plan query for index system SP4e7c82952015. Index fragment… Continue reading w3wp.exe: All query processing components are in ‘Failed’ status.