Spring boot application suddenly fails to start. SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder" - spring

Question

I m new to spring. I was writing spring boot applications with maven in last few days and had no issue in building or running on windows with STS. Then today for packaging i created a new project and and tried to build it with maven using win command prompt. Build failed and said that theres no compiler set("Perhaps your'e using a JRE"). Then I set JAVA_HOME in system variables and retried but then it started giving me
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder"
SLF4J: Defaulting to no-operation (NOP) logger implementation
....
Caused by:
java.lang.ClassNotFoundException:ch.qos.logback.classic.turbo.TurboFilter
Now I can't run any app which were working fine earlier either with STS/Eclipse, that error pops up.
I deleted .m2 and rebuilt.still not working.
Tried in a different windows pc with a fresh STS installation. It also doesn't work. this pops up.
Did they change libraries?
I deleted JAVA_HOME and retried.But no success.
I'm using a pretty simple pom and an application.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.pmanu</groupId>
<artifactId>testMaven</artifactId>
<version>0.0.1-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.6.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<properties>
<java.version>1.8</java.version>
</properties>
</project>
AppStart.java
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#RestController
#SpringBootApplication
public class AppStart {
public static void main(String[] args) {
SpringApplication.run(AppStart.class, args);
}
#RequestMapping("/")
public String get(){
return "Hello";
}
}
Please Help. I'd prefer to go ahead with spring 1.5.6.RELEASE artifacts.
I saw some answers saying that a logging jar like log4j has to be added to classpath.
But isn't maven parent supposed to have them configured? If there's any other proper way I'd prefer not to add an unnecessay dependancy for my applications.
How come this arised all of a sudden?