What are the common problems when app cannot connect to Excel?

[Jack]

Hello,
I have developed the stand alone application which interacts
with Excel spreadsheet.
It works fine on most Windows and computers, but from time to time I have
message from the user that my app cannot 'find' any opened spreadsheets, but
they are opened.
I wonder, what can cause that? What should I advise user to do?
Reinstalling Excel does not help.
I am using vbasic and Excel automation.
Your comments appreciated,
Jack

 

[Chip Pearson]

You might want to post the relevant portion of the code.

Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)

 

[Jack]

I do not believe it is my code related.
As I said it works 99% times.
I need to know what causes that 1% failure.
Please see below:
===============
Public WithEvents moExcelApp As Excel.Application


Set moExcelApp = GetObject(, "Excel.Application")
If moExcelApp Is Nothing Then 'when not sheet is opened
Set moExcelApp = CreateObject("Excel.Application")
If moExcelApp Is Nothing Then
Debug.Print "Excel app NOT found!"
ExcelApp = 1: Exit Sub
Else
moExcelApp.EnableEvents = True
End If
End If

 

[Jack]

Cordially you are, but what about my question?
Anything more to add, Chip?
Jack

 

[Jack]

Anyone else to pitch on that subject?
Anybody had that problem before?
I cannot believe it.
In the last 5 years, I encountered at least about 50 computers where Excel
automation did not work!
Jack

 

[Tim Williams]

Without code it's hard to speculate. Was it always consistent on each
"problem" computer ?
Antivirus SW ? Hidden open instance of Excel ?

Tim

 

[Tim Williams]

Without code it's hard to speculate.  Was it always consistent on each
"problem" computer ?
Antivirus SW ?  Hidden open instance of Excel ?

Tim

To elaborate: if there are >1 instances of Excel open then getobject
returns a reference to a random instance. If your expected
spreadsheet isn't open in that instance then your code may fail.

Tim