Reading in the old data file and re-calculating may cause an error. The reasons include: •Case file is broken •When the settings of the case file have changed •A calculation model variable in the case file has changed •The Partition is changed to parallel As a countermeasure, to start the Fluent, after initializing read the cas file, and re-compute the dat file. You can calculate almost without a problem. Note: If the saved case file is corrupted, you will need to re-create the case file itself.