Nullpointerexception while editing data sets in Eclipse BIRT 4.2.1

Do you sometimes get null pointer exceptions while editing a data set in BIRT? Your error log states something like:

java.lang.NullPointerException
    at org.eclipse.datatools.sqltools.sqlbuilder.SQLBuilder.setControlStateSize(SQLBuilder.java:1287)
    at org.eclipse.datatools.sqltools.sqlbuilder.SQLBuilder.saveWindowStateInfo(SQLBuilder.java:1233)
    at org.eclipse.datatools.sqltools.sqlbuilder.SQLBuilder.getWindowStateInfo(SQLBuilder.java:1218)
    at org.eclipse.birt.report.data.oda.jdbc.dbprofile.ui.internal.sqb.SQLBuilderDesignState.createSQBInput(SQLBuilderDesignState.java:93)
    at org.eclipse.birt.report.data.oda.jdbc.dbprofile.ui.internal.sqb.SQLBuilderDesignState.(SQLBuilderDesignState.java:46)

...

or

java.lang.NullPointerException
    at org.eclipse.datatools.sqltools.sqlbuilder.SQLBuilder.setControlStateSize(SQLBuilder.java:1287)
    at org.eclipse.datatools.sqltools.sqlbuilder.SQLBuilder.saveWindowStateInfo(SQLBuilder.java:1233)
    at org.eclipse.datatools.sqltools.sqlbuilder.SQLBuilder.getWindowStateInfo(SQLBuilder.java:1218)
    at org.eclipse.birt.report.data.oda.jdbc.dbprofile.ui.internal.sqb.SQLBuilderDesignState.createSQBInput(SQLBuilderDesignState.java:93)
    at org.eclipse.birt.report.data.oda.jdbc.dbprofile.ui.internal.sqb.SQLBuilderDesignState.(SQLBuilderDesignState.java:46)

? Then I have a workaround hint for you: edit the file in XML, look for the dataset section that causes the problem and delete its whole section  . Save and after that, the nullpointer Exception should be gone. Make sure to have backups before you change anything so you can always roll back.