Created attachment 30024 [details] Test code that demonstrates the bug Although CellRangeAddress supports whole column ranges like A:A and Excel supports it for conditional formatting, POI throws the following exception in case you try to do it (e.g. using CellRangeAddress.valueOf("A:A")) Exception in thread "main" java.lang.IllegalArgumentException: Minumum row number is 0 at org.apache.poi.ss.util.CellRangeAddressBase.validateRow(CellRangeAddressBase.java:63) at org.apache.poi.ss.util.CellRangeAddressBase.validate(CellRangeAddressBase.java:51) at org.apache.poi.hssf.usermodel.HSSFSheetConditionalFormatting.addConditionalFormatting(HSSFSheetConditionalFormatting.java:139) at org.apache.poi.hssf.usermodel.HSSFSheetConditionalFormatting.addConditionalFormatting(HSSFSheetConditionalFormatting.java:172) at org.apache.poi.hssf.usermodel.HSSFSheetConditionalFormatting.addConditionalFormatting(HSSFSheetConditionalFormatting.java:182) at TestConditionnalFormatWholeColumn.main(TestConditionnalFormatWholeColumn.java:18) (the same test is also done for XSSF so I suppose it is also affected)
Encountered same bug with XSSF