I was trying intensively various optimization setting in the autorouter dialog. I was selecting "Evaluate" after autorouter finishes and then "Continue" and then "Cancel" to start autorouting process again. Overall, I tried it about 10 times. But now Eagle starts crashing every time I click on autorouter button. It seems to me that the board file gets corrupted, because other boards work fine. I also noted that DRU file grew up from the initial 3k to 65k size. I have a 4-layer board 3x4 inches in size, routing grid 1mil and the board grid 20mil. The board file size also increased from about 300k to 32MB. I hope I will find a backup version that still works.
Any idea what I did wrong? What should I do to avoid such crashes/corruptions in the future?
Eagle version: latest.