I've run into a bug where all of the displayed elements on the screen lock up, but the rest of the game (audio, cursor, buttons, everything that I could manage to find by clicking on where buttons should be) runs fine. If I tab out and back in, the cursor will change and the buttons will still be clickable, but it's otherwise a clear window.

The only thing I've done to reproduce it so far is going into one of the management tabs, such as the trade&resources, military, or diplomacy screens. The freeze happens when I click the button, before actually displaying the selected screen.

I've found it happens more often after turn 100+, and if I quickly switch between two different management tabs at the beginning of a turn, when the AI is still playing. It's otherwise pretty random, though. I'll keep trying to find something that triggers it reliably.

Here's the last autosave it generated, on the turn I most recently had the bug:

AutoSave 825.zip

Most recent diagonstics file:

Diagnostics - 2017'06'08 @1822'09''.zip

Output log:

output_log.txt