Hi Koll,
Please see if you intended to make connections as in the file attached. This is a common problem that I have also encountered many times, especially when I was using 32-bit OptiSystem (I don’t know if it has anything to do with that) and when I use a lot of subsystems.
The problem is, you make a connection and then look inside a subsystem or save the file. After that, you see that connection is gone! And of course you cannot connect it again, as “cannot connect an already connected port”. But what is really going on is that the connection is established and if you close the software and then open the file again, you can see it there. So every time you see an already established connection not being there, restart the software.
Regards