no funciona webservice

Hola a todos
estoy trratando de levantar un servicio web en mi servidor pero me da el
siguiente error y nos e a que se debe.
espero em puedan ayudar

<?xml version="1.0" encoding="utf-8" ?>
- <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
- <soap:Body>
- <soap:Fault>
<faultcode>soap:Server</faultcode>
<faultstring>System.Web.Services.Protocols.SoapException: El servidor no
puede procesar la solicitud.
> System.IO.FileNotFoundException: No se encuentra el archivo o el
nombre del ensamblado yvfdcqzu.dll o una de sus dependencias.
Nombre de archivo: "yvfdcqzu.dll" at
System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase,
Boolean isStringized,
Evidence assemblySecurity, Boolean throwOnFileNotFound, Assembly
locationHint, StackCrawlMark& stackMark) at
System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef,
Boolean stringized, Evidence assemblySecurity, StackCrawlMark& stackMark)
at System.Reflection.Assembly.Load(AssemblyName assemblyRef,
Evidence assemblySecurity) at
System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly() at
System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly()
at System.Xml.Serialization.Compiler.Compile() at
System.Xml.Serialization.TempAssembly..ctor(XmlMapping[] xmlMappings) at
System.Xml.Serialization.XmlSerializer.FromMappings(XmlMapping[] mappings)
at System.Web.Services.Protocols.SoapServerType..ctor(Type type,
ProtocolsEnum versionsSupported)
at System.Web.Services.Protocols.SoapServerProtocol.Initialize()
at System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type,
HttpContext context, HttpRequest request, HttpResponse response, Boolean&
abortProcessing) Pre-bind state information LOG:
Where-ref bind. Location = C:\WINDOWS\TEMP\yvfdcqzu.dll LOG:
Appbase = file:///C:/Intranet/WebServiceCajas 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: Attempting download of new URL
file:///C:/WINDOWS/TEMP/yvfdcqzu.dll.
Fin del seguimiento de la pila de la excepción
interna </faultstring>
<detail />
</soap:Fault>
</soap:Body>
</soap:Envelope>

Desde ya muchas gracias