On the server, I can see the following entry:

[2013/10/11 19:27:00.450,488] Engine is not handled, probably out of licenses…
[2013/10/11 19:27:00.450,488] sqlFreeConnection with fReturnToPool=false (error handler)
[2013/10/11 19:27:00.450,488] SQL Server connection has been destroyed…

I guess that the Pro! installation is not removed correctly with the uninstall. As we only have Endpoint licenses, the server cannot accept the client. How can the bogus old Pro license be removed from the client?

Daniel