title: CRM 2011: Plug-in - Could not load file or assembly 'Microsoft.Xrm.Client'
body: <p>I am looking to build a fairly simple plug in that calculates the amount of "units" used &amp; remaining.
  I have two custom entites <code>bc_learninglicences</code> &amp; <code>bc_llbalance</code>, the plug - in fires on create of <code>bc_llbalance</code> and another for update.  </p>
  
  <pre><code>bc_llbalance: Contains
      bc_learninglicense (Look up field on bc_learninglicences / bc_name)
      bc_units (units that are used by this record)
  
  bc_learninglicences: Contains 
      bc_name
      bc_unitsquantity (This is set to the total qty of units)
      bc_unitsused (this needs to inherit the sum of "bc_units" on "bc_llbalance")
      bc_unitsremaining ( simply bc_unitsquantity - bc_unitsused )
  </code></pre>
  
  <p>Ok so I have included the code which is obviously not finished as I have just been trying to figure out how to get <code>bc_unitsused</code> to inherit the sum... 
  this code builds without error. however CRM errors:</p>
  
  <blockquote>
    <p>Unexpected exception from plug-in (Execute): LearningLicenses.LearningLicenses: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Xrm.Client, Version=5.0.9690.2165</p>
  </blockquote>
  
  <p>I have a short deadline to build this as the system is due to go live soon, however I cannot move forward with this error which I don't understand...</p>
  
  <p>Either help with error or code/solution will be appreciated at this point as I'm behind on the time frame for this project.</p>
  
  <p>p.s I am new to developing for CRM 2011 with only a few weeks/ few projects experience. </p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using Microsoft.Xrm.Sdk;
  using Microsoft.Xrm.Sdk.Query;
  using Microsoft.Xrm.Sdk.Messages;
  using System.Text.RegularExpressions;
  using System.ServiceModel;
  
  namespace LearningLicenses
  {
      public class LearningLicenses : IPlugin
      {
  
          public void Execute(IServiceProvider serviceProvider)
          {
              try
              {
  
                  // Obtain the execution context from the service provider.
                  Microsoft.Xrm.Sdk.IPluginExecutionContext context = (Microsoft.Xrm.Sdk.IPluginExecutionContext)
                      serviceProvider.GetService(typeof(Microsoft.Xrm.Sdk.IPluginExecutionContext));
  
                  //Extract the tracing service for use in debugging sandboxed plug-ins.
                  ITracingService tracingService =
                      (ITracingService)serviceProvider.GetService(typeof(ITracingService));
  
                  if (context.InputParameters.Contains("Target") &amp;&amp;
                          context.InputParameters["Target"] is Entity)
                   {
  
                       // Obtain the target entity from the input parmameters.
                       Entity entity = (Entity)context.InputParameters["Target"];
  
                  IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
                  IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);
  
                  EntityReference a = (EntityReference)entity.Attributes["bc_learninglicense"];// ((EntityReference)targetEntity.Attributes["bc_learninglicense"]).Id;
  
  
                  if (entity.LogicalName == "bc_llbalance")
                          try
                          {  
  
                              //fetchxml to get the sum total of estimatedvalue
                              string value_sum = string.Format(@"         
                      &lt;fetch distinct='false' mapping='logical' aggregate='true'&gt; 
                          &lt;entity name='bc_llbalance'&gt;
                              &lt;attribute name='bc_units' alias='units_sum' aggregate='sum' /&gt;
                                 &lt;filter type='and'&gt;
                                  &lt;condition attribute='bc_learninglicense' operator='eq' value='{0}' uiname='' 
                                 &lt;/filter&gt;
                          &lt;/entity&gt;
                      &lt;/fetch&gt;", a.Id);
  
                              FetchExpression fetch = new FetchExpression(value_sum);
                              EntityCollection value_sum_result = service.RetrieveMultiple(fetch);
                              var TotalValue = "";
                              // decimal TotalValue = 0;
                              foreach (var c in value_sum_result.Entities)
                              {
                                  TotalValue = ((string)((AliasedValue)c["value_sum"]).Value);
                              }
  
                              Entity llc = new Entity("bc_learninglicences");
                              llc.Id = a.Id;
                              llc.Attributes.Add("bc_unitsused", TotalValue);
  
                              service.Update(llc);
  
                          }
                          catch (FaultException ex)
                          {
                              throw new InvalidPluginExecutionException("An error occurred in the plug-in.", ex);
                          }
                  }
  
              }
              catch (FaultException ex)
              {
                  throw new InvalidPluginExecutionException("An error occurred in the plug-in.", ex);
              }
          }
      }
   }
  
  
  
  THE ERROR : 
  
  Unhandled Exception: System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]: Unexpected exception from plug-in (Execute): LearningLicenses.LearningLicenses: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Xrm.Client, Version=5.0.9690.2165, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.Detail: 
  &lt;OrganizationServiceFault xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/xrm/2011/Contracts"&gt;
    &lt;ErrorCode&gt;-2147220956&lt;/ErrorCode&gt;
    &lt;ErrorDetails xmlns:d2p1="http://schemas.datacontract.org/2004/07/System.Collections.Generic" /&gt;
    &lt;Message&gt;Unexpected exception from plug-in (Execute): LearningLicenses.LearningLicenses: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Xrm.Client, Version=5.0.9690.2165, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.&lt;/Message&gt;
    &lt;Timestamp&gt;2013-01-22T10:09:22.0275105Z&lt;/Timestamp&gt;
    &lt;InnerFault i:nil="true" /&gt;
    &lt;TraceText&gt;
  
  [LearningLicenses: LearningLicenses.LearningLicenses]
  [c1b35170-c563-e211-8c6d-b499bafd5e5b: LearningLicenses.LearningLicenses: Create of bc_llbalance]
  
  
  &lt;/TraceText&gt;
  &lt;/OrganizationServiceFault&gt;
  </code></pre>