I hope someone can help me - I'm getting desperate now as my app needs
to go to production RSN :-(

I have an ASP.Net C# app that is failing with "File or assembly name
System.Data, or one of its dependencies, was not found."

It does not happen all the time, only occasionally - it could be a day
before it happens or a few minutes.
The routine, System.Web.Security.WindowsAuthenticationModule.OnAuthenticate,
gets called for every web page opened, so it is working 99% of the
time.  Just not all the time.

I have seen posts here about this problem, which were down to people
running beta versions of .Net and then installing the production
version on top.

Whilst I did some of the development on a Release Candidate, the
actual machine this problem occurs on never had a release candidate
installed - just the redistributable and SP2.

Do any of you guru's out there have any ideas what might be causing
this?
I have enclosed a stack trace for more info.

Many thanks in advance,

Tony.

======================================================================
Server Error in '/Camelot2UAT' Application.
--------------------------------------------------------------------------------

File or assembly name System.Data, or one of its dependencies, was not
found.
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.IO.FileNotFoundException: File or assembly
name System.Data, or one of its dependencies, was not found.

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.

Assembly Load Trace: The following information can be helpful to
determine why the assembly 'System.Data' could not be loaded.

=== Pre-bind state information ===
LOG: DisplayName = System.Data
 (Partial)
LOG: Appbase = file:///E:/WebApps/Camelot2
LOG: Initial PrivatePath = bin
Calling assembly : (Unknown).
===

LOG: Policy not being applied to reference at this time (private,
custom, partial, or location-based assembly bind).
LOG: Post-policy reference: System.Data
LOG: Attempting download of new URL
file:///C:/WINNT/Microsoft.NET/Framework/v1.0.3705/Temporary ASP.NET
Files/camelot2uat/ef00d73d/8672731f/System.Data.DLL.
LOG: Attempting download of new URL
file:///C:/WINNT/Microsoft.NET/Framework/v1.0.3705/Temporary ASP.NET
Files/camelot2uat/ef00d73d/8672731f/System.Data/System.Data.DLL.
LOG: Attempting download of new URL
file:///E:/WebApps/Camelot2/bin/System.Data.DLL.
LOG: Attempting download of new URL
file:///E:/WebApps/Camelot2/bin/System.Data/System.Data.DLL.
LOG: Attempting download of new URL
file:///C:/WINNT/Microsoft.NET/Framework/v1.0.3705/Temporary ASP.NET
Files/camelot2uat/ef00d73d/8672731f/System.Data.EXE.
LOG: Attempting download of new URL
file:///C:/WINNT/Microsoft.NET/Framework/v1.0.3705/Temporary ASP.NET
Files/camelot2uat/ef00d73d/8672731f/System.Data/System.Data.EXE.
LOG: Attempting download of new URL
file:///E:/WebApps/Camelot2/bin/System.Data.EXE.
LOG: Attempting download of new URL
file:///E:/WebApps/Camelot2/bin/System.Data/System.Data.EXE.

Stack Trace:

[FileNotFoundException: File or assembly name System.Data, or one of
its dependencies, was not found.]
   System.Reflection.Assembly.nLoad(AssemblyName fileName, String
codeBase, Boolean isStringized, Evidence assemblySecurity, Boolean
throwOnFileNotFound, Assembly locationHint, StackCrawlMark& stackMark)
+0
   System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef,
Boolean stringized, Evidence assemblySecurity, StackCrawlMark&
stackMark) +307
   System.Reflection.Assembly.InternalLoad(String assemblyString,
Evidence assemblySecurity, StackCrawlMark& stackMark) +68
   System.Reflection.Assembly.Load(String assemblyString) +19
   System.Runtime.Serialization.Formatters.Binary.BinaryAssemblyInfo.GetAssembly()
+18
   System.Runtime.Serialization.Formatters.Binary.ObjectReader.GetType(BinaryAssemblyInfo
assemblyInfo, String name) +158
   System.Runtime.Serialization.Formatters.Binary.ObjectMap..ctor(String
objectName, String[] memberNames, BinaryTypeEnum[] binaryTypeEnumA,
Object[] typeInformationA, Int32[] memberAssemIds, ObjectReader
objectReader, Int32 objectId, BinaryAssemblyInfo assemblyInfo,
SizedArray assemIdToAssemblyTable) +128
   System.Runtime.Serialization.Formatters.Binary.ObjectMap.Create(String
name, String[] memberNames, BinaryTypeEnum[] binaryTypeEnumA, Object[]
typeInformationA, Int32[] memberAssemIds, ObjectReader objectReader,
Int32 objectId, BinaryAssemblyInfo assemblyInfo, SizedArray
assemIdToAssemblyTable) +54
   System.Runtime.Serialization.Formatters.Binary.__BinaryParser.ReadObjectWithMapTyped(BinaryObjectWithMapTyped
record) +330
   System.Runtime.Serialization.Formatters.Binary.__BinaryParser.ReadObjectWithMapTyped(BinaryHeaderEnum
binaryHeaderEnum) +71
   System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run()
+154
   System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler
handler, __BinaryParser serParser, Boolean fCheck, IMethodCallMessage
methodCallMessage) +228
   System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream
serializationStream, HeaderHandler handler, Boolean fCheck,
IMethodCallMessage methodCallMessage) +190
   System.EnterpriseServices.ComponentServices.ConvertToReturnMessage(String
s, IMessage mcMsg) +89
   System.EnterpriseServices.RemoteServicedComponentProxy.Invoke(IMessage
reqMsg) +848
   System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData&
msgData, Int32 type) +576
   Camelot.Database.Security.UserPreference.GetUserPreferences(String
DatabaseConnection, String sUserName) +0
   Camelot.BusinessObjects.Security.GetUserPreferences(String
sDatabaseConnection, String sUserName) +63
   Camelot.Web.Security.CamelotUser.RefreshPreferences() +128
   Camelot.Web.Security.CamelotUser..ctor(String sDatabaseConnection,
IPrincipal oPrincipal) +55
   Camelot.Web.Utility.GetCamelotUser(WindowsPrincipal oPrincipal)
+181
   Camelot.Web.Global.WindowsAuthentication_OnAuthenticate(Object
sender, WindowsAuthenticationEventArgs e) +157
   System.Web.Security.WindowsAuthenticationModule.OnAuthenticate(WindowsAuthenticationEventArgs
e) +24
   System.Web.Security.WindowsAuthenticationModule.OnEnter(Object
source, EventArgs eventArgs) +471
   System.Web.SyncEventExecutionStep.Execute() +60
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step,
Boolean& completedSynchronously) +87

--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:1.0.3705.288;
ASP.NET Version:1.0.3705.288

    Are you compiling some code against the RC and then distributing to
something different?  This is a no no.

--
          - Nicholas Paldino [.NET/C# MVP]