On the server machine:
Click on Start (for Windows 8 - click on Windows icon in the bottom left hand corner)
Type inetmgr and press ENTER – the Internet Information Services Manager will open
In the left hand side panel, open Sites, then open Default Website
Right-click on Console CSI, then go to Manage App, then click on Advanced Settings
Change Application Pool Data to .NET V2 CLASSIC
Click OK to save changes
Console should now be working with YesBookit again.
Note: in the screenshots below you don’t see the step ‘Right-click on Console CSI’