Bug: Game freezes during End Turn Phase

[winterholidays]

What information do I need to collect and provide for the full bug report data.

Description:
At the end of turns where many actions have been taken: buildings built, armies produced, sometimes the end of turn does not complete to reoffer play. This is repeatable for the saved game where the save stores the large number of actions taken. This problem is avoided by loading the monthly autosave, and taking fewer actions total.