Hello,

i running a java application on Linux maschines with openJdk 11. When creating a worksheet like 

 SXSSFWorkbook workbook = new SXSSFWorkbook(-1);
 SXSSFSheet sheet = workbook.createSheet("testsheet");

i run into follwoing error:

 java.lang.ClassCastException: class sun.font.CompositeFont cannot be cast to class sun.font.PhysicalFont (sun.font.CompositeFont and sun.font.PhysicalFont are in module java.desktop of loader 'bootstrap') at sun.font.SunFontManager.getDefaultPhysicalFont(SunFontManager.java:1086) ~[?:?]
at sun.font.SunFontManager.initialiseDeferredFont(SunFontManager.java:965) ~[?:?]
at sun.font.SunFontManager.findOtherDeferredFont(SunFontManager.java:903) ~[?:?]
at sun.font.SunFontManager.findDeferredFont(SunFontManager.java:919) ~[?:?]
at sun.font.SunFontManager.findFont2D(SunFontManager.java:2120) ~[?:?]
at java.awt.Font.getFont2D(Font.java:506) ~[?:?] at java.awt.Font.canDisplayUpTo(Font.java:2246) ~[?:?]
at java.awt.font.TextLayout.singleFont(TextLayout.java:469) ~[?:?]
at java.awt.font.TextLayout.<init>(TextLayout.java:530) ~[?:?]
at org.apache.poi.ss.util.SheetUtil.getDefaultCharWidth(SheetUtil.java:273) ~[poi-4.0.1.jar!/:4.0.1]
at org.apache.poi.xssf.streaming.AutoSizeColumnTracker.<init>(AutoSizeColumnTracker.java:117) ~[poi-ooxml-4.0.1.jar!/:4.0.1]
at org.apache.poi.xssf.streaming.SXSSFSheet.<init>(SXSSFSheet.java:82) ~[poi-ooxml-4.0.1.jar!/:4.0.1]
at org.apache.poi.xssf.streaming.SXSSFWorkbook.createAndRegisterSXSSFSheet(SXSSFWorkbook.java:664) ~[poi-ooxml-4.0.1.jar!/:4.0.1]
at org.apache.poi.xssf.streaming.SXSSFWorkbook.createSheet(SXSSFWorkbook.java:685) ~[poi-ooxml-4.0.1.jar!/:4.0.1]

Everthing works fine with openJdk10 or if i run it under windows. 
Hope you can help?