TypeLoadException

[Aberro-Bill]

Hi All,
I have code that loads a strongly named assembly using "Assembly.LoadFrom()"
and then finds all the types in the assembly using "GetTypes()". The code
has worked flawlessly in .NET 1.1 both on a development box and a clean box.
With .NET 2 it works on a development box, but NOT a clean box (XP pro, SP
2, .NET 1.1 and 2, all updates to this date). If I install the .NET 2 SDK
on my clean box it will work.
When it fails the message lists all the types in the assembly, so I know the
assembly loaded.

Why does this work on a development box or a box with the .NET 2 SDK, but
not a clean box?

What do I do to make it work on a clean box?

Thanks,
Bill

Here is a code snippet:

Assembly MyAssembly = Assembly.LoadFrom( FileName );
Type[] MyTypes = null;
try
{
MyTypes = MyAssembly.GetTypes();
}
catch (ReflectionTypeLoadException ex)
{
string msg = "";

foreach (Exception e in ex.LoaderExceptions)
{
if (e.Message != null) msg += e.Message + Environment.NewLine;
}
msg = "GetMyTypes() threw a TypeLoadException" + Environment.NewLine +
msg;
MessageBox.Show( msg );
}

 

[Kevin Yu [MSFT]]

Hi Bill,

If the app fails on loading the assembly file, could you please post the
exception message and stack trace here, so that I can do more research on
it.

Kevin Yu
Microsoft Online Community Support

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[Aberro-Bill]

Hi Kevin,

The app appears to succsssfully load the assembly file. The failure occurs
when I try to extract the types in it.
The exact type of the exception thrown by GetTypes is
"ReflectionTypeLoadException". Here is the list from that exception and the
stack trace.
Note: the loaded assembly has exactly 2 types in it and both their types
failed to load. Both types are derived from a base type "Observer" from a
dll in the GAC.
This works on a development box (app built with Visual Studio 2005), a box
with .NET 2 and .NET 2 SDK, but not a box with just .NET 2 (which is what my
customers will have)
My test boxes are XP SP2 Virtual PCs, all security patches up to date.
I have looked at the fusion log and it does not seem to show anything
unusual.
How can I get more diagnostic info about why GetTypes() is failing?

Bill

GetTypes() in LoadObservers threw a
System.Reflection.ReflectionTypeLoadException
Could not load type 'ContraTest.Default' from assembly 'Observers,
Version=1.5.0.0, Culture=neutral, PublicKeyToken=54150cdd1a8a7687'.
Could not load type 'ContraTest.NativeMDI' from assembly 'Observers,
Version=1.5.0.0, Culture=neutral, PublicKeyToken=54150cdd1a8a7687'.

Stack Trace:
at System.Reflection.Module.GetTypesInternal(StackCrawlMark& stackMark)
at System.Reflection.Assembly.GetTypes()
at ContraTest.Project.LoadObservers()

 

[Kevin Yu [MSFT]]

Hi Bill,

The Observer interface is in the visual J# library, which you might need to
install the Visual J# redistribution page. You can download the 2.0 version
from the following link:

http://www.microsoft.com/downloads/details.aspx?FamilyID=f72c74b3-ed0e-4af8-
ae63-2f0e42501be1&DisplayLang=en

Kevin Yu
Microsoft Online Community Support

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that others may learn and benefit from your issue.
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rights.)

 

[Aberro-Bill]

Hi Kevin,

ContraTest.Observer is my base class and these classes are namespaced so
there is no conflict with visual J# and there is no J# code - this
application is C# and some managed C++ but there is no C++ involved in this
part of the code. The types that fail to load are in my namespace ie
"ContraTest.Default".

So I don't see how your commment that we need the J# redist.

Bill

 

[Kevin Yu [MSFT]]

Hi Bill,

I mistake it for the Observer class in J#. On that clean machine, has your
strong named assembly been installed to GAC properly? In other words, you
can check in c:\windows\assembly folder to see if that assembly(with
correct name, version, culture and public key token) has been installed.

Kevin Yu
Microsoft Online Community Support

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[Aberro-Bill]

Yes, I have checked that the strongly named assembly is GACd, is the correct
version, etc.
I know it can work because if I take the clean machine with my software
installed and then install the .NET 2 SDK my software starts working just
fine and I have not touched the installation of my software. The only thing
different is I installed the .NET 2 SDK.

Thanks,
Bill

 

[Kevin Yu [MSFT]]

Hi Bill,

This seems to be a little weird. Could you please attach your assembly and
some code for me to test?

Kevin Yu
Microsoft Online Community Support

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When responding to posts, please "Reply to Group" via your newsreader so
that others may learn and benefit from your issue.
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rights.)