TheoTown

I decided to take a break from TheoTown and I played it today, when I entered, everything was normal, until a city I didn't crate popped up and I had to get 300 habitants, i could'not go back to the menu and play my old cities.
Does this have to do something with an update it is it a bug or glitch?

What version did you use? Because since Region is added in version 257, almost everything changed including the main menu being removed. You will get a region named "Theonia", and you start with a small area that you said you were required to get 300 habs

Currently using the latest Beta version, and why was the main menu removed? Does that mean I can no longer revisit my old cities?

With the main menu being changed doesn't mean it's removed. You can find it by clicking the gear icon (settings). And you can STILL play your old cities, by going to the region map (Globe icon) and you'll find two options on the top left of your screen

I just said so

Thanks for the help, now i can continue my city :D