NullReferenceException: GetLocaleCalendar()

[aliquid]

Regression from 2.4.1 to 2.5.1
Windows Server 2016 Core, 64-bit
.NET Framework 4.7.2

We do not call LocaleUtil.SetUserTimeZone(), never have. Not working with time zones, only converting dates to strings.

Fix maybe this?

private static ThreadLocal<TimeZone> userTimeZone
        = new ThreadLocal<TimeZone>(() => TimeZone.CurrentTimeZone);

System.NullReferenceException: Object reference not set to an instance of an object.
   at NPOI.Util.LocaleUtil.GetLocaleCalendar()
   at NPOI.SS.UserModel.DateUtil.GetJavaCalendar(Double date, Boolean use1904windowing, TimeZone timeZone, Boolean roundSeconds)
   at NPOI.XSSF.UserModel.XSSFCell.get_DateCellValue()
   at NPOI.SS.UserModel.DataFormatter.GetFormattedDateString(ICell cell)
   at NPOI.SS.UserModel.DataFormatter.FormatCellValue(ICell cell, IFormulaEvaluator evaluator)

[tonyqus]

hmm.... your concern makes sense. Maybe I should remove the SetUserTimeZone in 2.5.2

[vitalygoji]

I get excellent results when I process file with your awesome software.
Issue is when I try to read file second time, I get exception when I reading DateTime field (see below) .

Is there a workaround? I really need to fix it, its a production time and serious show stopper for whole our team.
Please help!

[tonyqus]

Which version of NPOI are you using? I suppose this issue should be resolved in NPOI 2.5.2

[shaiyu]

+1
2.5.1 -> 2.5.2