Solution
Your NI-Switch channel is set to be a Configuration Channel. Setting a channel as a Configuration Channel allows NI-SWITCH to use the channel for internal path creation but prevents making explicit connections. To revert the channel back to its default state, follow these steps:
1. Select your NI-Switch device in NI MAX.
2. Click
Configuration.
3. Click
Channels in the resulting window.
4. This window shows all channels that are set to be either Source or Configuration (Reserved For Routing) Channels. Remove the channel you are trying to connect from the "Reserved For Routing" list.