COMException (0x80010108 - RPC_E_DISCONNECTED) When Closing Excel.Workbook

Question

When I run the following code, I get the exception below:

''# NOTE: ExcelApp is a Private main form variable
Dim ReportBooks As Excel.Workbooks = ExcelApp.Workbooks
Dim ReportBook As Excel.Workbook = ReportBooks.Open(localFilename)
Dim ReportSheet As Excel.Worksheet = ReportBook.Sheets("Report")

''# Retreive data from sheet

ReleaseCOM(ReportSheet)
ReportBook.Close(True) ''# Error raised here
ReleaseCOM(ReportBook)
ReleaseCOM(ReportBooks)

ERROR:
COMException was unhandled
The object invoked has disconnected from its clients.
(Exception from HRESULT: 0x80010108 (RPC_E_DISCONNECTED))

Note: All data appears to have been retreived correctly.

Please help me diagnose and overcome this error.

Answer 1

I cannot say why it is failing based on the code you are showing.

Have you considered switching from Excel Automation using COM Interop to a 3rd party component?

SpreadsheetGear for .NET will let you load Excel workbooks and get values / get formatted text / recalculate formulas / etc... without the troubles associated with COM Interop.

You can see live ASP.NET samples here and download the free trial here if you want to try it yourself.

Disclaimer: I own SpreadsheetGear LLC

Answer 2

RPC_DISCONNECTED...the dreaded "The object invoked has disconnected from its clients." issue. There are a ton of causes to this, looks like you've covered the global variables issue with Excel.. Can you put the first ReleaseCOM(ReportSheet) below ReportBook(Close) and run it? Also, check out this.