ERROR StatusLogger Unrecognized format specifier

ERROR StatusLogger Unrecognized format specifier [d]
ERROR StatusLogger Unrecognized conversion specifier [d] starting at position 16 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [thread]
ERROR StatusLogger Unrecognized conversion specifier [thread] starting at position 25 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [level]
ERROR StatusLogger Unrecognized conversion specifier [level] starting at position 35 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [logger]
ERROR StatusLogger Unrecognized conversion specifier [logger] starting at position 47 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [msg]
ERROR StatusLogger Unrecognized conversion specifier [msg] starting at position 54 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [n]
ERROR StatusLogger Unrecognized conversion specifier [n] starting at position 56 in conversion pattern.
ERROR StatusLogger No log4j2 configuration file found. Using default configuration: logging only errors to the console.
ERROR StatusLogger Unrecognized format specifier [d]
ERROR StatusLogger Unrecognized conversion specifier [d] starting at position 16 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [thread]
ERROR StatusLogger Unrecognized conversion specifier [thread] starting at position 25 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [level]
ERROR StatusLogger Unrecognized conversion specifier [level] starting at position 35 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [logger]
ERROR StatusLogger Unrecognized conversion specifier [logger] starting at position 47 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [msg]
ERROR StatusLogger Unrecognized conversion specifier [msg] starting at position 54 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [n]
ERROR StatusLogger Unrecognized conversion specifier [n] starting at position 56 in conversion pattern.

In short, the problem arises when application classes are packaged in uber jar using maven shade plugin. While for log4j2 version 2.8.1 the fix is still pending, the suggested workaround is to update maven pom.xml with extra configuration settings for shade plugin as follow:

<project xmlns=""
             xmlns:xsi=""
             xsi:schemaLocation=" ">

        . . . . .

        <build>
            . . . . .
            <plugins>
                . . . . .
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-shade-plugin</artifactId>
                    <version>2.4.1</version>
                    <configuration>
                        <filters>
                            <filter>
                                <artifact>*:*</artifact>
                                <excludes>
                                    <exclude>META-INF/*.SF</exclude>
                                    <exclude>META-INF/*.DSA</exclude>
                                    <exclude>META-INF/*.RSA</exclude>
                                </excludes>
                            </filter>
                        </filters>
                        <transformers>
                            <transformer
                                    implementation="com.github.edwgiz.mavenShadePlugin.log4j2CacheTransformer.PluginsCacheFileTransformer"/>
                        </transformers>
                    </configuration>
                    <executions>
                        <execution>
                            <phase>package</phase>
                            <goals>
                                <goal>shade</goal>
                            </goals>
                        </execution>
                    </executions>
                    <dependencies>
                        <dependency>
                            <groupId>com.github.edwgiz</groupId>
                            <artifactId>maven-shade-plugin.log4j2-cachefile-transformer</artifactId>
                            <version>2.1</version>
                        </dependency>
                    </dependencies>
                </plugin>
                . . . . .
            </plugins>
        . . . . .
        </build>
        . . . . .
        <pluginRepositories>
            <pluginRepository>
                <id>oss.sonatype.org</id>
                <name>OSS Sonatype Staging</name>
                <url>https://oss.sonatype.org/content/groups/staging</url>
            </pluginRepository>
        </pluginRepositories>
        . . . . .
    </project>