$ cat TestConfig.xml
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
          "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<module name="Checker">
    <property name="charset" value="UTF-8"/>
    <property name="severity" value="warning"/>
    <property name="haltOnException" value="false"/>

<module name="Translation">
  <property name="id" value="Translation1" />
</module>
<module name="Translation">
  <property name="baseName" value="^.*$"/>
  <property name="id" value="Translation2" />
  <property name="requiredTranslations" value="es"/>
</module>
<module name="Translation">
  <property name="baseName" value="^.*$"/>
  <property name="id" value="Translation3" />
  <property name="requiredTranslations" value="es, fr"/>
</module>

</module>

$ java -Xmx3024m -jar /home/ricky/opensource/checkstyle/target/checkstyle-8.17-SNAPSHOT-all.jar -c TestConfig.xml -f xml -o results.xml /home/ricky/regression_repositories/openjdk7 -e /home/ricky/regression_repositories/openjdk7/.git
Exception in thread "main" java.lang.IllegalArgumentException: Malformed \uxxxx encoding.
    at java.util.Properties.loadConvert(Properties.java:574)
    at java.util.Properties.load0(Properties.java:391)
    at java.util.Properties.load(Properties.java:341)
    at com.puppycrawl.tools.checkstyle.checks.TranslationCheck.getTranslationKeys(TranslationCheck.java:481)
    at com.puppycrawl.tools.checkstyle.checks.TranslationCheck.checkTranslationKeys(TranslationCheck.java:442)
    at com.puppycrawl.tools.checkstyle.checks.TranslationCheck.finishProcessing(TranslationCheck.java:255)
    at java.util.ArrayList.forEach(ArrayList.java:1255)
    at com.puppycrawl.tools.checkstyle.Checker.process(Checker.java:221)
    at com.puppycrawl.tools.checkstyle.Main.runCheckstyle(Main.java:390)
    at com.puppycrawl.tools.checkstyle.Main.runCli(Main.java:313)
    at com.puppycrawl.tools.checkstyle.Main.execute(Main.java:180)
    at com.puppycrawl.tools.checkstyle.Main.main(Main.java:119)