There are too many problems to count. I got a message with the subject "Mortgage in principal" and no text. Same with pensions.

The browser opens new pages without hiding old ones.

Inbox count is wrong.

Buttons aren't responsive (no, I don't mean mobile design). They give no indication that something is happening.

Dragging windows is buggy.

There is no loading animation on clicking "next turn", nothing that indicates that the month has passed. Just add a dark overlay with a black and white loading bar and show the date afterwards.

I tried this in Chromium and Firefox and the problems are the same.