0.86 Sequence contains more than one matching element

After i upgrade ClosedXML from 0.85 to 0.86 i can’t save my Workbooks anymore. When i downgrade to 0.85 everything works again.

Stacktrace:

System.InvalidOperationException
Sequence contains more than one matching element.
StackTrace:
   bei System.Linq.Enumerable.Single[TSource](IEnumerable`1 source, Func`2 predicate)
   bei ClosedXML.Excel.XLWorkbook.GenerateWorkbookStylesPartContent(WorkbookStylesPart workbookStylesPart, SaveContext context) in C:\Git\ClosedXML\ClosedXML\Excel\XLWorkbook_Save.cs:Zeile 2610.
   bei ClosedXML.Excel.XLWorkbook.CreateParts(SpreadsheetDocument document) in C:\Git\ClosedXML\ClosedXML\Excel\XLWorkbook_Save.cs:Zeile 252.
   bei ClosedXML.Excel.XLWorkbook.CreatePackage(String filePath, SpreadsheetDocumentType spreadsheetDocumentType, Boolean validate) in C:\Git\ClosedXML\ClosedXML\Excel\XLWorkbook_Save.cs:Zeile 104.
   bei ClosedXML.Excel.XLWorkbook.Save(Boolean validate) in C:\Git\ClosedXML\ClosedXML\Excel\XLWorkbook.cs:Zeile 452.
   bei ClosedXML.Excel.XLWorkbook.Save() in C:\Git\ClosedXML\ClosedXML\Excel\XLWorkbook.cs:Zeile 432.

And my Code

var wb = new XLWorkbook(FILEPATH);
wb.Save();   // Just Opening und Saving is Enough.

I hope the Stacktrace is enough. Happens with different Excel Files on my side. If you need more Information, just ask.

[BenKmann]

Cloned it and yep, it works with the develop Branch 👍

[igitur]

The PR has been merged into the develop branch. I’d appreciate it if you could pull the develop branch and check that it solves your issue. Thanks.