Failed to introspect Class [org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration]

If you have below dependency for spring-boot-starter-tomcat in you POM, remove scope part of it.

Existing:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>

New:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>

The error is helpful in that it can’t find the required class javax.servlet.Filter and a common way to have this class is through this dependency:

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>

which ends up pulling in org.apache.tomcat.embed:tomcat-embed-core

We were seeing this locally because when running the Spring Boot application from Intellij we didn’t have the option ‘Include dependencies with “Provided” scope’ in the Run/Debug Configuration ticked.

I think this dependency:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

Made a conflict with this one:

<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-core</artifactId>
    <type>jar</type>
</dependency>

Why do you need the last one? I think you don’t need it, because you already has starter for security, so remove it.

Try adding this to your pom.xml:

<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-config</artifactId>
    <version>4.0.1.RELEASE</version>
</dependency>

It helped me.