.NET Questions and Solutions

Symptoms
After you rename the columns of a DataTable object in the DataSet, if you try to refer to the columns in case-insensitive manner, you receive the following exception:

An unhandled exception of type ‘System.ArgumentException’ occurred in system.data.dll
Additional information: Column ‘ColumnName’ does not belong to table ‘Tablename’.
Resolution
When you first create a column in a DataTable object of a DataSet, the name is added to two indexes: a case-sensitive index and a case-insensitive index. When you rename the column in a DataTable object, the new name is not added to the case-insensitive index. Therefore, when you rename a DataTable column, the ColumnName becomes case-sensitive.

Symptoms
An unhandled exception may occur under the following circumstances: An ASP.NET worker process (Aspnet_wp.exe) runs under the default ASPNET account.
-and-
You do not enable impersonation on that application.
-and-
You try to connect to or write to an Access database. Under these circumstances, you may receive one of the following exceptions:

The Microsoft Jet database engine cannot open the file ‘C:\Nwind.mdb’. It is already opened exclusively by another user, or you need permission to view its data.

Operation must use an updateable query.
Resolution
Because of security concerns, the ASP.NET worker process runs under the default ASPNET account. If you do not enable impersonation for an application, all of the threads that run the requests for that application run under the process account.
This problem occurs because the ASPNET account does not have sufficient permissions to connect to or write to an Access database.

Symptoms
When you build or run a client application (such as a Microsoft Visual C++ application) that runs anSQL statement on a Microsoft Jet data source, the client application may fail with anunhandled exception. You may receive an error message that is similar to thefollowing:

Unknown The error message may also contain the following error code:

0×80040e14 This problem may occur even if theclient application runs a valid SQL statement.
Resolution
This problem occurs because the Microsoft Jet database driver .dll file (Msjtes40.dll) is not correctly registered.

Symptoms
An illegal instruction (C00000FD) exception or an access violation (C0000005) exception occurs in the Intersite Messaging service (ismserv.exe). The exception causes ismserv.exe to crash.
Resolution
This problem occurs if a function in the Adsiis.dll component leaves a released cache item in the server cache when a remote procedure call (RPC) error occurs. When a subsequent client request tries to use the released cache item, the illegal instruction exception or the access violation exception occurs.

Symptoms
You modify the Microsoft Office Outlook Web Access user interface by following the steps in the “Specifying Icons for Custom Content Items” section of the following Microsoft Web site:
http://msdn2.microsoft.com/en-us/library/bb891875(EXCHG.80).aspx(http://msdn2.microsoft.com/en-us/library/bb891875(EXCHG.80).aspx)When you use Outlook Web Access to browse to a Microsoft Exchange Server 2007 mailbox, an exception that blocks the regular operation occurs. Additionally, the following events are logged in the Application event log:
Event Type: Error
Event Source: MSExchange Common
Event Category: General
Event ID: 4999
Description:
Watson report about to be sent to dw20.exe for process id: <process ID>, with parameters: E12IIS, <processor>, <version>, OWA, M.E.C.Owa, M.E.C.O.C.ThemeManager.RenderThemeFilePath, System.IndexOutOfRangeException, <address>, <version>. ErrorReportingEnabled: True
Event Type: Error
Event Source: Microsoft Exchange Server
Event Category: None
Event ID: 5000
Description:
EventType e12iis, P1 <processor>, P2 <version>, P3 owa, P4 m.e.c.owa, P5 m.e.c.o.c.thememanager.renderthemefilepath, P6 system.indexoutofrangeexception, P7 <address>, P8 <version>, P9 NIL, P10 NIL.
Resolution
To resolve this problem, install Update Rollup 2 for Exchange Server 2007 Service Pack 1. For more information about Update Rollup 2 for Exchange Server 2007 Service Pack 1, see the following Exchange Help topic:
Description of Update Rollup 2 for Exchange Server 2007 Service Pack 1 (http://go.microsoft.com/fwlink/?LinkId=152558)For more information about how to obtain the latest Exchange service pack or update rollup, see the following Exchange Help topic:
How to Obtain the Latest Service Pack or Update Rollup for Exchange 2007(http://go.microsoft.com/fwlink/?LinkId=152570)

Symptoms
You may receive an “Access violation while reading from location 0×0FB04000″ exception in the worker thread of the mail program.
Resolution
Offset and length parameters for CWtvMailApp::GetRequestParam that are not valid cause the mail program to try to access memory that is beyond the message’s data.