Exception with message "Error in Cell: B6-Invalid formula:"

Conversion of one of the file failed while converting excel file to PDF. We are using Aspose.Cells(Ver. 7.1.1.0). Following is the exception we got. Please provide fix asap.

Code snippet:
Workbook workbook=null;
workbook = new Workbook(sourceFilePath);
Aspose.Cells.SaveOptions saveOptions = null;
saveOptions = new Aspose.Cells.XlsSaveOptions();
saveOptions.CachedFileFolder = Path.GetTempPath();
saveOptions.SaveFormat = Aspose.Cells.SaveFormat.Pdf;
if (workbook != null)
workbook.Save(destinationFilePath, saveOptions);

Exception:
1/26/2012 11:18:11 PM
Message: HandlingInstanceID: 7ee6b139-950e-436e-b3a1-1da689e2e6c7
An exception of type 'Aspose.Cells.CellsException' occurred and was caught.
2012-01-26 18:18:11Z
Aspose.Cells.CellsException, Aspose.Cells, Version=5.1.1.0, Culture=neutral, PublicKeyToken=716fcc553a201e56
Error in Cell: B6-Invalid formula:"='[70]Furniture & Fix.- perquisite'!N8+'[70]Furniture & Fix.'!N8".
Aspose.Cells in file: C:\WINDOWS\TEMP\IntraLinks\f55bcaba-a229-49dc-87bd-a7dac9250891.xlsx
Formula
System.Collections.ListDictionaryInternal
Void x1f490eac106aee12(Aspose.Cells.Cell, System.String, Byte, Boolean)
at x9d2539cac3622db3.x40937ad35b1cf5f7.x1f490eac106aee12(Cell xe6de5e5fa2d44af5, String xef81f2df12e64618, Byte x804d9de34bfbea97, Boolean x3ca77743a16d7720)
at Aspose.Cells.Cell.set_x899ab9e9fa6303bc(String xbcea506a33cf9111)
at xabb58b8f2887ff8e.x7661ca2b53df3da9.xb953ef709de3d2ab(XmlTextReader xb9763b0038341e6c, Int32 x3e0a106e44f5f6eb, Int32 x5b0d56b787e972e9)
at xabb58b8f2887ff8e.x7661ca2b53df3da9.xd9c6f1ce6ced5eb4(XmlTextReader xb9763b0038341e6c, Int32 x8e17ff07bb5aefbf)
at xabb58b8f2887ff8e.x7661ca2b53df3da9.x5b9fbbb55c31a1b7(XmlTextReader xb9763b0038341e6c)
at xabb58b8f2887ff8e.x7661ca2b53df3da9.x06b0e25aa6ad68a9(XmlTextReader xb9763b0038341e6c)
at xabb58b8f2887ff8e.x9d49ab444acbddce.x72bde2882aefe5af(x1f5f0dd7560ed867 xd9171314ec0b2957, String x7d11dcd405070662)
at xabb58b8f2887ff8e.x9d49ab444acbddce.xc3266f78bb6c4216(x1f5f0dd7560ed867 xd9171314ec0b2957, String x7d11dcd405070662)
at xabb58b8f2887ff8e.x9d49ab444acbddce.x88ae89d546ee9fdf()
at xabb58b8f2887ff8e.x9d49ab444acbddce.x06b0e25aa6ad68a9()
at Aspose.Cells.Workbook.Open(Stream stream, FileFormatType type)
at Aspose.Cells.Workbook.Open(String fileName)
at Intralinks.Common.Utilities.AsposeConverter.ConvertXlsToPdf(String sourceFilePath, String destinationFilePath) in c:\ilbuilds\pdfconv\build_trunk\CommonUtilities\AsposeConverter.cs:line 71
at Intralinks.Common.Utilities.CommonUtilities.ConvertOfficeDocsToPDF(String sourceFile, String destinationFolder, Boolean useOriginalFileName) in c:\ilbuilds\pdfconv\build_trunk\CommonUtilities\CommonUtilities.cs:line 1385
Category: Logging Exception
Priority: 1
EventId: 100
Severity: Error
Title:Enterprise Library Exception Handling
Machine: WDPDPF01
Application Domain: ILPDFConversionService.exe
Process Id: 7476
Process Name: C:\PDFConvService\WOODDALE.pdfconv\instance5\Release\ILPDFConversionService.exe
Win32 Thread Id: 5192
Thread Name:
Extended Properties: Product Version - 3.0.24944.0

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Hi,

Thanks for your posting and using Aspose.Cells for .NET.

Please download and use the latest version:
Aspose.Cells
for .NET v7.1.2.1

it should fix the problems.

If the problem still occurs, then please provide us your xls/xlsx file which you are converting to pdf.

We will check it soon and help you asap.