What should I do if suddenly the broker lost his license, because this can also happen ?

Of course, this can happen, I'll tell you more, I had it, but this is a separate story

I really don't know, that's why you should pick a trustworthy broker since the beginning, real professionals, I use MetaTrader 4, they are the best forex brokers using metatrader , an excellent option to me because I really haven't lost anything working with them, they have excellent charting system, technical indicators, analytical tools and more.