DllNotFoundException after 4 years of use in .NET (Win 2K3)

[vitar30]

Hello all,

I'm using with no problem libgfl211.dll for about 4 years in my ASP.NET 1.1 application (on Windows Server 2003, IIS 6) to check uploaded image and it's size. Here's a sample of wrapper code that call DLL's gflLibraryInit method:

Code: Select all

<DllImport("libgfl211.dll", EntryPoint:="gflLibraryInit", _
SetLastError:=True, CharSet:=CharSet.Ansi, ExactSpelling:=True, _
CallingConvention:=CallingConvention.StdCall)> _
Protected Shared Function LibraryInit() As Int16
End Function

The same way are organized calls to other DLL's methods. DLL is placed in bin directory with application DLL (ASP.NET is compiled with VS 2003).

But from last week I've got exception:

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System.DllNotFoundException: ?
   at BS.Images.ImageParameters.LibraryInit()

The same is still working on Windows XP Pro. I've checked DLL on the server - it is not changed and binary check of it is OK. No changes were made on the server, except regular Windows updates.

Now I have no idea, what caused this exception and what to do. I've tried newer versions, such as libgfl282.dll with the same error.

[vitar30]

As it stopped working for unknown reason, it is started to work again as before with unknown reason. If I'll find a reason that caused a problem, I let you know about it.