After deploy a SharePoint SP1 farm I started Sharepoint Powershell cmd and I found the following error:
Method ‘Upgrade’ in type ‘Microsoft.SharePoint.WorkflowServices.WorkflowServiceApplicationProxy’ from assembly ‘Microsoft.SharePoint.Wor Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c’ does not have an implementation.
There’s an update that assumes you already have SP1 deployed – if you go back to Central Admin you’ll note the UI changes for O365 & Yammer are now showing up. The fix is to deploy one more hotfix to your server – you can download it from here: http://www.microsoft.com/en-us/download/details.aspx?id=42898
No reboot required – install the update, open up that PS window & you’re blissfully error free.
Albandrod's Memory 