Reason: decimal value is not valid for definition

This error message usually occurs when a decimal value is used in a context where only integers are allowed, such as when defining a constant or a data type. To fix the error, you need to either change the context to allow decimal values or convert the decimal value to an integer.

For example, if you are defining a constant with a decimal value, you can change it to use an integer value instead:

const int MY_CONSTANT = 42;

Alternatively, if you need to use decimal values, you can use a data type that supports decimal values, such as `decimal` in C#:

decimal myDecimalValue = 3.14159m;