title: Ninject Runtime Exception occuring frequently - System.InvalidOperationException: Collection was modified; enumeration operation may not execute
body: <p>I am using Ninject 2.2.1.0 with Ninject.Web 2.2.0.0 in a webforms application.</p>
  
  <p>I am getting daily error reports of the following...</p>
  
  <blockquote>
  <pre><code>System.InvalidOperationException: Collection was modified; enumeration
  </code></pre>
    
    <p>operation may not execute.
           at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource
    resource)
           at System.Collections.Generic.List<code>1.Enumerator.MoveNextRare()
           at System.Collections.Generic.List</code>1.Enumerator.MoveNext()
           at System.Linq.Enumerable.WhereSelectListIterator<code>2.MoveNext()
           at Ninject.Infrastructure.Language.ExtensionsForIEnumerableOfT.Map[T](IEnumerable</code>1
    series, Action`1 action) in
    c:\Projects\Ninject\ninject\src\Ninject\Infrastructure\Language\ExtensionsForIEnumerableOfT.cs:line
    22
           at Ninject.OnePerRequestModule.DeactivateInstancesForCurrentHttpRequest()
    in
    c:\Projects\Ninject\ninject\src\Ninject\OnePerRequestModule.cs:line
    63
           at Ninject.OnePerRequestModule.b__0(Object
    o, EventArgs e) in
    c:\Projects\Ninject\ninject\src\Ninject\OnePerRequestModule.cs:line
    36
           at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
           at System.Web.HttpApplication.ExecuteStep(IExecutionStep
    step, Boolean&amp; completedSynchronously)</p>
  </blockquote>
  
  <p>Seems to be occuring at peak times.  Is there a stable release with this patched yet?</p>