I am getting the error with following two imports in Eclipse:
import javafx.scene.control.Alert; import javafx.scene.control.Alert.AlertType;
The errors are: "The import javafx.scene.control.Alert cannot be resolved" and same is true for the 2nd import statement.
I am using Eclipse Version: Luna Service Release 2 (4.4.2) and have installed e(fx)clipse with latest JDK 1.8 (1.8.0_45).
There is no problem with other javafx related import statements, such as
import javafx.scene.control.Label; import javafx.scene.control.ListView; import javafx.scene.input.MouseEvent;
I had the same problem, until I installed the JDK 1.8.0_60. That's right, installing the latest JDK helped! 
After you install the latest JDK, change the settings on the Eclipse There are two steps to the process:
Select the appropriate JRE in Eclipse > Preferences > Java > Installed JREs as shown here:
- In
Project > Properties > Java Build Path, Add Library as depicted below:
I got the same problem on Eclipse (MacOSX Yosemite) this morning but yesterday everything worked... To solve the problem I just deselected the checkbox for another JDK in Project > Properties > Java Build Path restarted Eclipse, reselected the good one (JDK 1.8.0_60), restarted Eclipse again and voilà ! Just a weird bug with checkboxes...
Hope it ll help you.
