Problem opening Navision with a URL

I’m trying to open Navision using URLs like this one: navision://client/run?servername=DINGO% … ld1,Field3)%26servertype=MSSQL The other URL is similar. Problem: It opens a new instance of the client each time. Even if I add the forcenewinstance=no parameter to the links (which is supposed to be the default state) it still wants to open a new client. .