I am using EPPlus 2.8.0.2 library in my ASP.NET MVC 3 app to generate excel files. This application runs on IIS 6 on Windows Server 2003 R2.
The offending line is this:
xlsdoc.GetAsByteArray
xlsdoc is a properly loaded ExcelPackage object.
Generating small output is fine, but generating big output produces an error:
System.IO.IsolatedStorage.IsolatedStorageException: Initialization failed.
at System.IO.IsolatedStorage.IsolatedStorageFile.Init(IsolatedStorageScope scope)
at System.IO.IsolatedStorage.IsolatedStorageFile.GetStore(IsolatedStorageScope scope, Type domainEvidenceType, Type assemblyEvidenceType)
at MS.Internal.IO.Packaging.PackagingUtilities.ReliableIsolatedStorageFileFolder.GetCurrentStore()
at MS.Internal.IO.Packaging.PackagingUtilities.ReliableIsolatedStorageFileFolder..ctor()
at MS.Internal.IO.Packaging.PackagingUtilities.GetDefaultIsolatedStorageFile()
at MS.Internal.IO.Packaging.PackagingUtilities.CreateUserScopedIsolatedStorageFileStreamWithRandomName(Int32 retryCount, String& fileName)
at MS.Internal.IO.Packaging.SparseMemoryStream.SwitchModeIfNecessary()
at MS.Internal.IO.Packaging.SparseMemoryStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at MS.Internal.IO.Packaging.CompressEmulationStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at MS.Internal.IO.Packaging.CompressStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at MS.Internal.IO.Zip.ProgressiveCrcCalculatingStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at MS.Internal.IO.Zip.ZipIOModeEnforcingStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at System.IO.StreamWriter.Flush(Boolean flushStream, Boolean flushEncoder)
at System.IO.StreamWriter.Write(String value)
at System.IO.TextWriter.Write(String format, Object arg0)
at OfficeOpenXml.ExcelWorksheet.UpdateRowCellData(StreamWriter sw)
at OfficeOpenXml.ExcelWorksheet.SaveXml()
at OfficeOpenXml.ExcelWorksheet.Save()
at OfficeOpenXml.ExcelWorkbook.Save()
at OfficeOpenXml.ExcelPackage.GetAsByteArray(Boolean save)
at OfficeOpenXml.ExcelPackage.GetAsByteArray()
at ReportCenterLib.ReportGenerator.GenerateStream(DataTable result, String reporttitle, String inputparmstr, String conndescs, String username, String outputtype, String templatefile) in D:\PROJECTS\reportcentermvc\sources\ReportCenterLib\ReportGenerator.vb:line 450
at ReportCenterMVC.ReportCenterMVC.ReportController.Generate(Int64 id, IList`1 conns, IDictionary`2 parms, String outputtype) in D:\PROJECTS\reportcentermvc\sources\ReportCenterMVC\Controllers\ReportController.vb:line 218
I suspect EPPlus tries to create temporary files using IsolatedStorage, but didn't have permission to write to IsolatedStorage. I have changed the application pool identity to 'local system', and the error disappears.
How do I avoid this error while using 'network service' identity?