Can't exit out of the research tree!!

[Slateman]

First off, hi! :) First post :D

Now, my problem . . .

Have a little problem. I finished the research tree and . . . . it won't let me exit out of the screen. Normally you click on the next research quest and the check mark lights up in the bottom right. Well I finished it and . . . . nada. Doesn't light up. Have to hit Ctrl + Alt + Del and exit out of the game :(

[sick]

Check 2nd and 3rd Era for unresearched techs.

[Slateman]

That did it. Guess I just did't notice :D