The openfire server reports the following error:
2020-05-21 12:51:43,435 main ERROR Unknown object "logger" of type org.apache.logging.log4j.core.config.LoggerConfig is ignored: try nesting it inside one of: ["Appenders", "Loggers", "Properties", "Scripts", "CustomLevels"]. 2020-05-21 12:51:43,443 main ERROR Unknown object "root" of type org.apache.logging.log4j.core.config.LoggerConfig is ignored: try nesting it inside one of: ["Appenders", "Loggers", "Properties", "Scripts", "CustomLevels"].
The configuration for logging should be updated from previous to new log4j version.