TokenMgrError for Umlauts

The file had a german umlaut as variable name at line 72:
String $18KgwErfüllt = "...";

Workaround: Change the name of the variable
String $18KgwErfuellt = "...";

[INFO] [javancss:report]
TokenMgrError in D:\svn\xxx-ratingplatform\tags\xxx-ratingplatform-0.1.0\src\main\java\de\xxx\xxx\rating\report\RatingReport.java
Lexical error at line 72, column 24. Encountered: "\u00bc" (188), after : ""

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[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Can not execute Sonar

Embedded error: Unable to execute mojo
Lexical error at line 72, column 24. Encountered: "\u00bc" (188), after : ""
[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
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