Index: lams_common/src/java/org/lamsfoundation/lams/util/excel/ExcelUtil.java
===================================================================
diff -u -r9836d653441ba5744aa399b472c18e9d6d6d7947 -r719aba3a889834f41ba93af0c98a2a1235b63d5f
--- lams_common/src/java/org/lamsfoundation/lams/util/excel/ExcelUtil.java	(.../ExcelUtil.java)	(revision 9836d653441ba5744aa399b472c18e9d6d6d7947)
+++ lams_common/src/java/org/lamsfoundation/lams/util/excel/ExcelUtil.java	(.../ExcelUtil.java)	(revision 719aba3a889834f41ba93af0c98a2a1235b63d5f)
@@ -237,7 +237,8 @@
 
 	for (int columnIndex : columnWidths.keySet()) {
 	    // one unit is 1/256 of character width, plus some characters for padding
-	    sheet.setColumnWidth(columnIndex, (columnWidths.get(columnIndex) + 4) * 256);
+	    // maximum is 255 characters
+	    sheet.setColumnWidth(columnIndex, Math.min(255, columnWidths.get(columnIndex) + 4) * 256);
 	}
     }
 
@@ -371,7 +372,6 @@
 		}
 	    }
 
-	    
 	    // Store maximum number of characters in each column.
 	    // XLXS format processing is done chunk by chunk and it is append only, so this information needs to be stored on the fly.
 	    Integer existingColumnWidth = columnWidths.get(columnIndex);