Object reference not set to an instance of an object

Hi,
My application works fine on the localhost but spits this error as soon
as I put it on the server. I know this error occurs when an object has
not been instantiated prior to a reference, but why shouldn't it happen
in the localhost?
Here's what the the whole error msg looks like:
Server Error in '/' Application.
----
--
Object reference not set to an instance of an object.
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.NullReferenceException: Object reference not
set to an instance of an object.
Source Error:
An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.
Stack Trace:
[NullReferenceException: Object reference not set to an instance of an
object.]
Auction002.login.UserExists() in
C:\Inetpub\wwwroot\Auction002\login.aspx.vb:82
Auction002.login.btnLogin_Click(Object sender, EventArgs e) in
C:\Inetpub\wwwroot\Auction002\login.aspx.vb:54
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +108
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePo
stBackEvent(String
eventArgument) +57
System.Web.UI.Page. RaisePostBackEvent(IPostBackEventHandler
sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
+33
System.Web.UI.Page.ProcessRequestMain() +1292
----
--
Version Information: Microsoft .NET Framework Version:1.1.4322.2300;
ASP.NET Version:1.1.4322.2300
I'll really appreciate any help.
thanxHi nemo,
I cannot answer why it would happen in one environment and not in another,
as I have no idea what sort of object is being used, and for what purpose.
Neither do I know what may be different about the 2 environments or the 2
applications. Assuming that the applications are identical (and for me that
is a large assumption), it would have to be something about how the
application interacts with the enviroment.
One (of many) guess I could take would be that your app is logging in the
user with some sort of external dependency, either on Active Directory,
local machine users, or a database. Perhaps something is preventing access
to the external resource.
I would suggest you take a look at
C:\Inetpub\wwwroot\Auction002\login.aspx.vb:82
Auction002.login.btnLogin_Click(Object sender, EventArgs e)
This would be line 82 in that code file. Figure out what object references
are there, and which of them might or might not exist. If you have Visual
Studio.Net, you can set a break point there and examine the objects that are
in use. Otherwise, you can use Try/Catch to catch the exception, and perhaps
log the details of it to the Event Log.
HTH,
Kevin Spencer
Microsoft MVP
.Net Developer
Paranoia is just a state of mind.
"nemo" <pallabs@.gmail.com> wrote in message
news:1125329035.242227.112120@.g47g2000cwa.googlegroups.com...
> Hi,
> My application works fine on the localhost but spits this error as soon
> as I put it on the server. I know this error occurs when an object has
> not been instantiated prior to a reference, but why shouldn't it happen
> in the localhost?
> Here's what the the whole error msg looks like:
>
> Server Error in '/' Application.
> ----
--
> Object reference not set to an instance of an object.
> 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.NullReferenceException: Object reference not
> set to an instance of an object.
> Source Error:
> An unhandled exception was generated during the execution of the
> current web request. Information regarding the origin and location of
> the exception can be identified using the exception stack trace below.
>
> Stack Trace:
>
> [NullReferenceException: Object reference not set to an instance of an
> object.]
> Auction002.login.UserExists() in
> C:\Inetpub\wwwroot\Auction002\login.aspx.vb:82
> Auction002.login.btnLogin_Click(Object sender, EventArgs e) in
> C:\Inetpub\wwwroot\Auction002\login.aspx.vb:54
> System.Web.UI.WebControls.Button.OnClick(EventArgs e) +108
> System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.Raise
PostBackEvent(String
> eventArgument) +57
> System.Web.UI.Page. RaisePostBackEvent(IPostBackEventHandler
> sourceControl, String eventArgument) +18
> System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
> +33
> System.Web.UI.Page.ProcessRequestMain() +1292
>
> ----
--
> Version Information: Microsoft .NET Framework Version:1.1.4322.2300;
> ASP.NET Version:1.1.4322.2300
>
> I'll really appreciate any help.
> thanx
>
Thanks for your response Kevin. Yes the applications are identical and
I'm indeed using VS.Net. I checked line 82 in the file where the error
is occuring and here's the code:
Dim i, j As Integer
Dim UserArray() As String
UserArray = Application("userarray")
j = UserArray.Length <-- this is line 82
I have defined the application variable "userarray" in the
"Application_Start" subroutine in the global.asax file before it
reaches the above code.
Still wondering why this should not be a problem in localhost but would
in the server.
thanx
Hi nemo,
In that case, the problem lies in your setting of the
Applcation("userarray") in the Application_Start. Apparently, something is
preventing it from being created. It is probably null.
HTH,
Kevin Spencer
Microsoft MVP
.Net Developer
Paranoia is just a state of mind.
"nemo" <pallabs@.gmail.com> wrote in message
news:1125333765.190206.275700@.o13g2000cwo.googlegroups.com...
> Thanks for your response Kevin. Yes the applications are identical and
> I'm indeed using VS.Net. I checked line 82 in the file where the error
> is occuring and here's the code:
> Dim i, j As Integer
> Dim UserArray() As String
> UserArray = Application("userarray")
> j = UserArray.Length <-- this is line 82
>
> I have defined the application variable "userarray" in the
> "Application_Start" subroutine in the global.asax file before it
> reaches the above code.
> Still wondering why this should not be a problem in localhost but would
> in the server.
> thanx
>

Object reference not set to an instance of an object

Hi,

My application works fine on the localhost but spits this error as soon
as I put it on the server. I know this error occurs when an object has
not been instantiated prior to a reference, but why shouldn't it happen
in the localhost?

Here's what the the whole error msg looks like:

Server Error in '/' Application.
------------------------

Object reference not set to an instance of an object.
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.NullReferenceException: Object reference not
set to an instance of an object.

Source Error:

An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an
object.]
Auction002.login.UserExists() in
C:\Inetpub\wwwroot\Auction002\login.aspx.vb:82
Auction002.login.btnLogin_Click(Object sender, EventArgs e) in
C:\Inetpub\wwwroot\Auction002\login.aspx.vb:54
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +108

System.Web.UI.WebControls.Button.System.Web.UI.IPo stBackEventHandler.RaisePostBackEvent(String
eventArgument) +57
System.Web.UI.Page.RaisePostBackEvent(IPostBackEve ntHandler
sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCol lection postData)
+33
System.Web.UI.Page.ProcessRequestMain() +1292

------------------------
Version Information: Microsoft .NET Framework Version:1.1.4322.2300;
ASP.NET Version:1.1.4322.2300

I'll really appreciate any help.

thanxHi nemo,

I cannot answer why it would happen in one environment and not in another,
as I have no idea what sort of object is being used, and for what purpose.
Neither do I know what may be different about the 2 environments or the 2
applications. Assuming that the applications are identical (and for me that
is a large assumption), it would have to be something about how the
application interacts with the enviroment.

One (of many) guess I could take would be that your app is logging in the
user with some sort of external dependency, either on Active Directory,
local machine users, or a database. Perhaps something is preventing access
to the external resource.

I would suggest you take a look at

C:\Inetpub\wwwroot\Auction002\login.aspx.vb:82
Auction002.login.btnLogin_Click(Object sender, EventArgs e)

This would be line 82 in that code file. Figure out what object references
are there, and which of them might or might not exist. If you have Visual
Studio.Net, you can set a break point there and examine the objects that are
in use. Otherwise, you can use Try/Catch to catch the exception, and perhaps
log the details of it to the Event Log.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Paranoia is just a state of mind.

"nemo" <pallabs@.gmail.com> wrote in message
news:1125329035.242227.112120@.g47g2000cwa.googlegr oups.com...
> Hi,
> My application works fine on the localhost but spits this error as soon
> as I put it on the server. I know this error occurs when an object has
> not been instantiated prior to a reference, but why shouldn't it happen
> in the localhost?
> Here's what the the whole error msg looks like:
>
> Server Error in '/' Application.
> ------------------------
> Object reference not set to an instance of an object.
> 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.NullReferenceException: Object reference not
> set to an instance of an object.
> Source Error:
> An unhandled exception was generated during the execution of the
> current web request. Information regarding the origin and location of
> the exception can be identified using the exception stack trace below.
>
> Stack Trace:
>
> [NullReferenceException: Object reference not set to an instance of an
> object.]
> Auction002.login.UserExists() in
> C:\Inetpub\wwwroot\Auction002\login.aspx.vb:82
> Auction002.login.btnLogin_Click(Object sender, EventArgs e) in
> C:\Inetpub\wwwroot\Auction002\login.aspx.vb:54
> System.Web.UI.WebControls.Button.OnClick(EventArgs e) +108
> System.Web.UI.WebControls.Button.System.Web.UI.IPo stBackEventHandler.RaisePostBackEvent(String
> eventArgument) +57
> System.Web.UI.Page.RaisePostBackEvent(IPostBackEve ntHandler
> sourceControl, String eventArgument) +18
> System.Web.UI.Page.RaisePostBackEvent(NameValueCol lection postData)
> +33
> System.Web.UI.Page.ProcessRequestMain() +1292
>
> ------------------------
> Version Information: Microsoft .NET Framework Version:1.1.4322.2300;
> ASP.NET Version:1.1.4322.2300
>
> I'll really appreciate any help.
> thanx
Thanks for your response Kevin. Yes the applications are identical and
I'm indeed using VS.Net. I checked line 82 in the file where the error
is occuring and here's the code:

Dim i, j As Integer
Dim UserArray() As String
UserArray = Application("userarray")
j = UserArray.Length <-- this is line 82

I have defined the application variable "userarray" in the
"Application_Start" subroutine in the global.asax file before it
reaches the above code.

Still wondering why this should not be a problem in localhost but would
in the server.

thanx
Hi nemo,

In that case, the problem lies in your setting of the
Applcation("userarray") in the Application_Start. Apparently, something is
preventing it from being created. It is probably null.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Paranoia is just a state of mind.

"nemo" <pallabs@.gmail.com> wrote in message
news:1125333765.190206.275700@.o13g2000cwo.googlegr oups.com...
> Thanks for your response Kevin. Yes the applications are identical and
> I'm indeed using VS.Net. I checked line 82 in the file where the error
> is occuring and here's the code:
> Dim i, j As Integer
> Dim UserArray() As String
> UserArray = Application("userarray")
> j = UserArray.Length <-- this is line 82
>
> I have defined the application variable "userarray" in the
> "Application_Start" subroutine in the global.asax file before it
> reaches the above code.
> Still wondering why this should not be a problem in localhost but would
> in the server.
> thanx

Object reference not set to an instance of an object.

When I click button the following error occurs. What does this mean and how to remove it. Please help.

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.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 25: MsgBox("Hi there")
Line 26: 'Put user code to initialize the page here
Line 27: End Sub
Line 28:
Line 29: Private Sub Button1_ServerClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.ServerClick

Source File: c:\inetpub\wwwroot\WebForm1.aspx.vb Line: 27

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
localhost.WebForm1.Button1_ServerClick(Object sender, EventArgs e) in c:\inetpub\wwwroot\WebForm1.aspx.vb:27
System.Web.UI.HtmlControls.HtmlInputButton.OnServerClick(EventArgs e) +108
System.Web.UI.HtmlControls.HtmlInputButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +57
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +138
System.Web.UI.Page.ProcessRequestMain() +1263Can you post lines 1 to 30 of WebForm1.aspx.vb? Because your error message suggests that you've mistakenly deleted some lines of code. Before you post the code, pleaseread this.

Even beyond that, there seems to be a number of problems with your code. I don't think that you can use the MsgBox function in ASP.NET. And having WebForm1.aspx.vb directly within your wwwroot folder seems problematic. Are you working through a book that introduces ASP.NET, or gone through theonline tutorials? If not, you should, aseveryone new to ASP.NET needs to go through the basics.
There is something in your code behind file that is told to do something. The problem is, it is not on your aspx page to do it. It has something to do with that MsgBox. I am not sure of the entire procedure though.
See, Since this is the direct VB code there is no question of "<>" code blocks coming into picture. Since I have been working on VB6 for last 2 years so I find VB code very easy. When I was going through the Help File of ASP.net on creating web page I came across this code. It says that when You double click on the control the "...aspx.vb" file opens and You can write your code for button click or any such events there.
When I run the Page the code behind (in the aspx.vb module) doesn't run but when I put them in html it runs.
So my problem is how to run the code from aspx.vb module of Visualstudio.net package which seems so easy to code and understand for me.
Sounds like you are not telling the aspx page where the codebehind source is located. Top line should read something like this:
<%@. Page language="vb" CodeBehind="DesktopDefault.aspx.vb" AutoEventWireup="false" Explicit="True"Inherits="DotNetNuke.DesktopDefault" %>
which is thenamespace.classname