In the PAC Control command Open Outgoing Communications, if you specify an incorrectly formatted connection string (for example, tcp::pppp where pppp is a TCP port number), a -70 will be returned, and the socket the call attempted to open will become permanently unavailable for use.
Once all available sockets have been rendered unusable by this problem, an error -49 (No More Streams) will be returned, and it will not be possible to make any new Ethernet connections (user or host).
Opto 22 has resolved this issue.
Make sure the Ethernet connection string is correct before using it in the command Open Outgoing Communications.
If you have already run into this issue, reset or cycle power on the controller.
Alternatively, you can put PAC Manager into UDP (connectionless) mode and reboot that way. This can be helpful if you are not physically near the PAC. To make PAC Manager use UDP rather than TCP, create a text file containing only the letters udp. Save this file with the name options.def and place it in the folder where your PAC Manager exe is, for example, C:\Program Files (x86)\Opto22\PAC Project 9.3\Manager.exe. Close and re-open PAC Manager, and it will use UDP.