There was an unexpected error (type=Internal Server Error, status=500).
This error was found in running springboot.

There was an unexpected error (type=Internal Server Error, status=500).
Authentication failed for token submission [org.apache.shiro.authc. UsernamePasswordToken – null, rememberMe=false]. Possible unexpected error?(Typical or expected login exceptions should extend from AuthenticationException).
I had to rewrite it and found out that it was caused by Maven and the Thymeleaf dependency was added incorrectly.
Maybe I wrote it and @{} didn’t work correctly, so I took one from the internet and got the wrong one.
The original dependency was this

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

I ended up with this

<!-- https://mvnrepository.com/artifact/org.thymeleaf/thymeleaf -->
<dependency>
    <groupId>org.thymeleaf</groupId>
    <artifactId>thymeleaf</artifactId>
    <version>3.0.12.RELEASE</version>
</dependency>

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