"The provider could not determine the Object value" when accessing MSAccess database with ASP.NETV1

[Siegfried Heintze]

This program works fine on my desktop when I grant full control of the
MSAccess database to everyone. However, when I put it on my hosting service
with no impersonation, I now get this error (see below).
Can anyone suggest what the problem is?

When I turn on impersonation, I get "unspecified error". See below.

Thanks,
Siegfried

With no impersonation:
Server Error in '/keyword-job-search' Application.
----------------------------------------------------------------------------
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The provider could not determine the Object value. For example, the row was
just created, the default for the Object column was not available, and the
consumer had not yet set a new Object value.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: The provider could not
determine the Object value. For example, the row was just created, the
default for the Object column was not available, and the consumer had not
yet set a new Object value.

Source Error:
Line 194: OleDbDataAdapter oCMD = new
OleDbDataAdapter(concat(selJobPosting[nCmd]), concat(strConn));
Line 195: DataSet oDS = new DataSet();
Line 196: oCMD.Fill(oDS, "MyList");
Line 197: return oDS;
Line 198: }

With impersonation:

Server Error in '/keyword-job-search' Application.
----------------------------------------------------------------------------
----

Unspecified error
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Exception Details: System.Data.OleDb.OleDbException: Unspecified error

Source Error:

Line 194: OleDbDataAdapter oCMD = new
OleDbDataAdapter(concat(selJobPosting[nCmd]), concat(strConn));
Line 195: DataSet oDS = new DataSet();
Line 196: oCMD.Fill(oDS, "MyList");
Line 197: return oDS;
Line 198: }