Eclipse (Ctrl + Space) Is Not Working

1. Start Eclipse.
2. Go to "Window> Preferences > Java > Editor > Content Assist 
3. Insert this line in "Auto Activation Trigger for Java" box : ._abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
4. You are on Content Assist, open it, and press on advanced Check all check boxes. Look at the figures bellow.