Стал вопрос, как можно получить актуальные эти данные самому допустим?
//Формируем набор buildID нашего Firefox (у каждой версии свой)
Tuple<string, string>[] buildIDSet = {
Tuple.Create("57", "20171112125346"),
Tuple.Create("56", "20171024165158"), // 56.0.2
Tuple.Create("56", "20171002220106"), // 56.0.1
Tuple.Create("56", "20170926190823"),
Tuple.Create("55", "20170802111421"),
Tuple.Create("54", "20170608105825"),
Tuple.Create("53", "20170413192749"),
Tuple.Create("52", "20171206101620"), // 52.5.2
Tuple.Create("52", "20171107091003"), // 52.5.0
Tuple.Create("52", "20170316213829"),
Tuple.Create("51", "20170125094131"),
Tuple.Create("50", "20161104212021"),
Tuple.Create("49", "20161019084923")
};