Log4j Error: log4j-jul and log4j-to-jul Conflict, Missing SLF4J.Logger

This error message indicates that there is a conflict between two JAR files: 'log4j-jul' and 'log4j-to-jul'. These two JAR files are mutually exclusive and cannot be used together. The first one routes calls from Log4j to JUL (Java Util Logging), while the second one routes calls from Log4j to SLF4J (Simple Logging Facade for Java) and then to JUL.

In addition, the error message also indicates that there is a missing class: 'org.slf4j.Logger'. This class is part of the SLF4J library and is required by Log4j to work properly.

To resolve this issue, you need to remove one of the conflicting JAR files and ensure that all required libraries, including SLF4J, are properly included in your project's classpath.