<p>I'm trying to create a custom workflow action with an output parameter for error handling. Working from various examples, I can't get Parameter Direction="Out" to work.  Everything seems right, but when I try to assign the output to the "error" variable in SharePoint Designer, it places asterisks around it and flags it as a workflow error.  Here is what the action XML looks like:</p>

<pre><code>&lt;Action Name="Create Folder"
  ClassName="ActivityLibrary.CreateFolderActivityTest"
  Assembly="ActivityLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=xxxxxxxxxxx"
  AppliesTo="all"
  CreatesInList="ListId"
  Category="Custom"&gt;
  &lt;RuleDesigner Sentence="Create a folder %1 in the %2 base folder. If an error occurs it will be output to %3."&gt;
    &lt;FieldBind Field="FolderName" Text="folder name" Id="1"  /&gt;
    &lt;FieldBind Field="BaseFolderPath"  Text="folder path" Id="2"/&gt;
    &lt;FieldBind Field="OutError" DesignerType="ParameterNames" Text="out error" Id="3"/&gt;
  &lt;/RuleDesigner&gt;
  &lt;Parameters&gt;
    &lt;Parameter Name="FolderName" Type="System.String, mscorlib" Direction="In" /&gt;
    &lt;Parameter Name="BaseFolderPath" Type="System.String, mscorlib" Direction="In" /&gt;
    &lt;Parameter Name="OutError" Type="System.String, mscorlib" Direction="Out" /&gt;
  &lt;/Parameters&gt;
&lt;/Action&gt;
</code></pre>

[{'answer_id': 18993, 'author': 'Mauro', 'author_id': 2208, 'author_profile': 'https://Stackoverflow.com/users/2208', 'pm_score': 0, 'selected': False, 'text': '<p>Are you sure the issue is with the parameters and not maybe the variable in SPD?  Certainly nothing looks wrong with your XML.</p>\n\n<p>I always hated the way SPD and workflows make you create a variable within the workflow and another within the page to assign to the same value as the workflow variable.</p>\n'}, {'answer_id': 375112, 'author': 'slf', 'author_id': 13263, 'author_profile': 'https://Stackoverflow.com/users/13263', 'pm_score': 1, 'selected': False, 'text': '<p>I think you may want Direction="InOut" from the looks of the binding</p>\n'}, {'answer_id': 552913, 'author': 'Charlie', 'author_id': 466531, 'author_profile': 'https://Stackoverflow.com/users/466531', 'pm_score': 0, 'selected': False, 'text': '<p>Did you get anywhere with this?  I suspect the problem was more likely in your logic code rather than this xml (.actions) file.  It looks perfectly acceptable to me.</p>\n'}]
['https://Stackoverflow.com/questions/15053', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/1533/']