We might be using different logging framework in our application log4j or logback or any other framework. These frameworks are internally using slf4j API.In some case if we have different slf4j API in classpath or older version of slf 4j API causes below exception.

Caused by: java.lang.IllegalAccessError: tried to access field org.slf4j.impl.StaticLoggerBinder.SINGLETON from class org.slf4j.LoggerFactory
 at org.slf4j.LoggerFactory.<clinit>(LoggerFactory.java:60)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
 at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
 at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
 at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1098)
 ... 22 more

Solution:
We need to upgrade the slf 4j API to latest version, If your using maven we can add below dependency in pom.

<dependency>
     <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.7</version>
</dependency>