In SERVER-55788 for version 5.0.0, we added logic to log a warning when the client uses one of the deprecated op codes (OP_QUERY, OP_INSERT, etc.). The message indicates the use of a deprecated feature. Support for the deprecated op codes is being completely removed in 5.1.0, so in 5.1.0 the same warning will be logged but the operation will be rejected by the server. Customers should upgrade their driver to ensure that they are not relying upon the old op codes.

We should improve log message 5578800 in both the master and 5.0 branches to include a dochub link. This link should redirect to a page that explains the deprecation and removal of the old op codes, and also provides instructions regarding what the customer should do in order to avoid any disruption to their application.