Development Assistance Error custom config file

Hi,
I want to make a messages file for my plugin i am making but it gives me an error:

Here is my code:

Code:java

package com.SlagHoedje.Minigavers.SkyWars.handlers;
 
import java.io.File;
 
import org.bukkit.ChatColor;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.configuration.file.YamlConfiguration;
 
import com.SlagHoedje.Minigavers.SkyWars.Main;
 
public class MessageHandler {
 
private File file;
private FileConfiguration config;
 
public MessageHandler() {
file = new File(Main.getPlugin().getDataFolder(), "messages.yml");
 
if (!file.exists()) {
try {
file.createNewFile();
} catch (Exception e) {
e.printStackTrace();
}
}
 
config = YamlConfiguration.loadConfiguration(file);
}
 
public String getCaption(String name) {
return this.getCaption(name, true);
}
 
public String getCaption(String name, boolean color) {
String caption = this.config.getString(name);
if (caption == null) {
Main.getPlugin().getLogger().warning("Missing caption: " + name);
if (this.config.getString("CaptionNotFoundError") == null) {
return "Didn't find message: Ask staff for more info!";
}
caption = getCaption("CaptionNotFoundError").replaceAll("&caption", name);
}
 
if (color) {
caption = ChatColor.translateAlternateColorCodes('&', caption);
}
caption = getCaption("prefix") + caption;
return caption;
}
}

 

what is line 17?

 

Line 17:

Code:java

file = new File(Main.getPlugin().getDataFolder(), "messages.yml");