Alliance chat being empty a bug with the game, The Divine. It happens sometimes. It has happened to one of our allies, and it happened to me when I joined the alliance with my second base.
The fix for the chat being empty is to leave the alliance and rejoin the alliance again.
Hope this helps! Cheers
The S35 tank has HP of 22,620, DPS of 486.
The exact numbers might differ depending on the wonders (Versailles), library researches, university upgrades, etc. but this should give you an idea of the HP and DPS