The Model Regeneration box on the Model Generator tab:

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is used to control the frequency with which LINGO regenerates a model. Commands that will trigger the model generator are

•Solver|Solve,
•Solver|Generate,
•Solver|Model Statistics,
•Solver|Picture,
•Solver|Debug, and
•File|Export_File.

The choices available under this option are:

•Only when text changes — LINGO regenerates a model only when a change has been made to the model’s text since the last generation took place.
•When text changes or with external references — LINGO regenerates whenever a change is made to the model text or when the model contains references to external data sources (e.g., text files, databases, or spreadsheets.)
•Always — (default) LINGO always regenerates the model each time information regarding the generated model is needed.

LINGO defaults to always regenerating the model.