Duplicate local variable

Explanation of error:

This formula includes two local variables that share a name. Each local variable must have a name that is unique within the formula.

Example:

Let var = 42; Let var = 43; var * 2

In this example, two local variables have been defined with the same name: "var".

How to resolve this error:

Examine the formula and ensure that each local variable has a name that is unique within the formula.

The above example could be corrected by renaming one or both of the local variables, resulting in (for example) Let var1 = 42; Let var2 = 43; var1 * 2.