Unconfirmed internal error

[theking15]

Ingame Nick:theking15
Affected world(s):zz18
Browserpera GX
Reproduction steps:

1. .attack the city
2. .another attacks her and begins to conquer her with a colonization ship
3. .and not knowing it or wanting to attack so that you do not conquer it does not leave me jumping internal error making me lose that city or not letting me conquer another

Detailed error description (What you see): appears internal error has ocurred i try to conquer or defense my city

How it should be: I would have to let you attack the city so that you can defend it or conquer another city that you want but someone arrived before

Screenshot: