Comment 9 for bug 1074655

I'm seeing the same symptoms, but when a window of a production site is open (bakery, colosseum etc.). It takes several hours to trigger. I always play with the Message and Stock windows open, but found that when I closed them and left the production site window open, the game was still suffering from severe lag. Once the bug was triggered I could have the stock and message windows open and have no problem, but seconds after opening a production site window it would crawl to a halt again.

Once the production site window is closed the game usually reverts to its normal speed, and then when opened again it would lag. Saving and reloading the game restored normal operation until another few hours were played. I am not sure if the fact that I had the stock window open for several hours may have contributed to this bug so not sure if I should report a new bug or if this one needs re-opening.