title: What is causing "Automation error Unspecified error" on Worksheet_Activate?
body: <p>I have a worksheet named "Dates" (object name is A_Dates) that needs to be calculated when it is activated (It may be worth noting that this is in my Personal macro workbook). I regularly have workbooks open that have too many calculations in the for me to have auto-calculation on. So I have auto-calc set to manual, and the following code in the worksheet:</p>
  
  <pre><code>Private Sub Worksheet_Activate()
     A_Dates.Calculate
  End Sub
  </code></pre>
  
  <p>This has worked fine for the last 3 months, day-in and day-out. Yesterday, it stopped working. It now throws this error on the declaration line:</p>
  
  <pre><code>Microsoft Visual Basic
  Automation error
  Unspecified error
  [OK] [Help]
  </code></pre>
  
  <p>I have tried changing how I reference the sheet, using:</p>
  
  <pre><code>Sheets("Dates").Calculate
  </code></pre>
  
  <p>and</p>
  
  <pre><code>ActiveSheet.Calculate
  </code></pre>
  
  <p>to no avail. I've also included error handling:</p>
  
  <pre><code>On Error Resume Next
  </code></pre>
  
  <p>which doesn't prevent it. I've even gone so far as:</p>
  
  <pre><code>Private Sub Worksheet_Activate()
     On Error GoTo headache
     Sheets("Dates").Calculate
  Exit Sub
  
  headache:
     Exit Sub
  End Sub
  </code></pre>
  
  <p>and it still shows up. I am totally at a loss. Help?</p>
  
  <h1>Additional Information</h1>
  
  <p>I have the following references, and use all of them in various macros in this workbook:</p>
  
  <p>Visual Basic for Applications</p>
  
  <ul>
  <li>Microsoft Excel 12.0 Object Library</li>
  <li>OLE Automation</li>
  <li>Microsoft Office 12.0 Object Library</li>
  <li>Microsoft Scripting Runtime</li>
  <li>Microsoft Forms 2.0 Object Runtime</li>
  <li>Microsoft HTML Object Library</li>
  <li>Microsoft Internet Controls</li>
  <li>Microsoft ActiveX Data Objects 2.8 Library</li>
  <li>Microsoft ActiveX Data Objects Recordset 2.8 Library</li>
  </ul>