ControlDraw carries out checks on the integrity of a model when opening or selecting in the File manager. Specifically it now checks that all the table fields, queries and relationships in the model are up to date with the latest structure.
This can be switched off by deselecting "Check Model Structure on Opening" in Tools Utilities, but this is not recommended.
You can update a model using the Complete Update program.
You can also run this from the Model Advisor.
(At present this is in the early stages of development, but eventually it is intended to provide both step by step and (future) background methods to check the model.)