LoggerFactory is not a Logback LoggerContext but Logback is on the classpath

Same solution for maven:

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-thymeleaf</artifactId>    <version>1.5.1.RELEASE</version>    <exclusions>        <exclusion>            <groupId>ch.qos.logback</groupId>            <artifactId>logback-classic</artifactId>        </exclusion>    </exclusions></dependency>

i figured out

compile("org.springframework.boot:spring-boot-starter-security"){    exclude module: "spring-boot-starter-logging"    exclude module: "logback-classic"}compile("org.springframework.boot:spring-boot-starter-thymeleaf"){    exclude module: "logback-classic"}

The problem for me went on with: Either remove Logback or the competing implementation class org.apache.logging.slf4j.Log4jLoggerFactory loaded from log4j-slf4j-impl-2.12.0.jar

I added

configurations {    all {        exclude group: 'org.springframework.boot', module: 'spring-boot-starter-logging'        exclude group: 'ch.qos.logback', module: 'logback-classic'        exclude group: 'org.apache.logging.log4j', module: 'log4j-to-slf4j'    }}

to my gradle.build and also refreshed all project dependencies with the latest versions and the problem resolved.