Unable to create mutex when generating an Excel Report

I'm trying to generate an excel report which may sometimes contain large amount of data (approximately 25,000 records & 2.5 - 3MB) using EPPLUS. This works fine in the development environment (Windows Server 2012 R2 Standard), but fails for large data sets when I deployed it.

It throws the exception - "IsolatedStorageException: Unable to create mutex. (Exception from HRESULT: 0x80131464)".

I changed the Application Pool identity to 'LocalSystem' and set Load User profile - True, but it didn't resolve the issue.

Stack Trace:

[IsolatedStorageException: Unable to create mutex. (Exception from HRESULT: 0x80131464)]
   System.IO.IsolatedStorage.IsolatedStorageFile.Open(String infoFile, String syncName) +0
   System.IO.IsolatedStorage.IsolatedStorageFile.Lock(Boolean& locked) +370
   System.IO.IsolatedStorage.IsolatedStorageFileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, IsolatedStorageFile isf) +474
   System.IO.IsolatedStorage.IsolatedStorageFileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, IsolatedStorageFile isf) +35
   MS.Internal.IO.Packaging.SafeIsolatedStorageFileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, ReliableIsolatedStorageFileFolder folder) +102
   MS.Internal.IO.Packaging.PackagingUtilities.CreateUserScopedIsolatedStorageFileStreamWithRandomName(Int32 retryCount, String& fileName) +276
   MS.Internal.IO.Packaging.SparseMemoryStream.EnsureIsolatedStoreStream() +31
   MS.Internal.IO.Packaging.SparseMemoryStream.SwitchModeIfNecessary() +383
   MS.Internal.IO.Packaging.CompressEmulationStream.Write(Byte[] buffer, Int32 offset, Int32 count) +73
   MS.Internal.IO.Packaging.CompressStream.Write(Byte[] buffer, Int32 offset, Int32 count) +376
   MS.Internal.IO.Zip.ProgressiveCrcCalculatingStream.Write(Byte[] buffer, Int32 offset, Int32 count) +108
   MS.Internal.IO.Zip.ZipIOModeEnforcingStream.Write(Byte[] buffer, Int32 offset, Int32 count) +120
   System.IO.StreamWriter.Flush(Boolean flushStream, Boolean flushEncoder) +224
   System.IO.StreamWriter.Write(String value) +147
   OfficeOpenXml.ExcelWorksheet.UpdateRowCellData(StreamWriter sw) +7885
   OfficeOpenXml.ExcelWorksheet.SaveXml() +1082
   OfficeOpenXml.ExcelWorksheet.Save() +704
   OfficeOpenXml.ExcelWorkbook.Save() +1295
   OfficeOpenXml.ExcelPackage.GetAsByteArray(Boolean save) +144
   OfficeOpenXml.ExcelPackage.GetAsByteArray() +52
   PLM.Report.Reports.ReportViewer.SetExcel(Dictionary`2 args) +1017
   PLM.Report.Reports.ReportViewer.Page_Load(Object sender, EventArgs e) +926
   System.Web.UI.Control.LoadRecursive() +71
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3178