gistfile1.txt

using System.Threading.Tasks;

class Test
{
    static async Task Main()
    {
        // (Include the error message in the post.) 
        _ = await Condition() ? await M1() : await M2();
    }
     
    static Task<bool> Condition() => Task.FromResult(true);
    static Task M1() => Task.CompletedTask;
    static Task M2() => Task.CompletedTask;
}