This is an error from Redshift that the value is too big for their "numeric" type.
My best guess is that you should find something in your flow that you are summing and would have very big sums and multiply it by 1.0 before summing.
Otherwise I would recommend contacting Tableau Support. We will have to review your logs and your flow in detail to give more specific advice.
It looks like there was a precision discrepancy issue in the original Redshift tables that had to be solved either by replacing the tables and setting the data types or by using CAST to convert the numbers in the metric fields in a sql query.