Sage 300 v2016 PU2 on Windows 2012 R2 Server

All works fine on the desktop version, however, when trying to post a batch within the Web Screens, whether it be AP or AR Invoice, AR Receipt, GL Batch etc, it gets to the point where the screen says Processing but that's has far as it goes.  It will allow me to close the screen and when I go back to the batch list the batch is still there waiting to be posted, not Post in Progress or Posted.  It does allow me to make changes and save customer details, and it will allow me to post things like Bank Entries.

Has anyone come across this?

Thanks