[Solved] No overload for method, takes 0 arguments?

You changed the function to require one parameter… so now all of your old function calls, which passed no parameters, are invalid.

Is this parameter absolutely necessary, or is it a default value?

if it is a default then use a default parameter or an overload:

//`variable` will be 0 if called with no parameters
public static int[] ArrayWorkings(int variable=0)  

// pre-C# 4.0
public static int[] ArrayWorkings()
{
    ArrayWorkings(0);
}

public static int[] ArrayWorkings(int variable)
{
    // do stuff
}