Object reference not set to an instance of an object

[nemo]

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.RaisePostBackEvent(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

 

[Kevin Spencer]

Hi 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.

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.RaisePostBackEvent(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

 

[nemo]

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

 

[Kevin Spencer]

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.