Hello. I bought an Apollo Twin in about 2012. I have the latest version of Logic Pro and I love the orphaned Guitar Rig. I recently bought a Two Notes Captor X. I was having a hard time making everything work together but I finally figured it out.
If you're having problems, do this: Connect the Captor X and Apollo Twin via XLR cables. Open UA Console. Click on Cue Outputs. Make sure the source is on Mix with both Line 3/4 and HP (I'm using headphones). In Logic click File and New for a new project. You're going to open an Audio track. Input and output both 1 and 2.
You should have downloaded Torpedo Remote V5 already. Run your speaker out from your amp into the speaker in (red ring) of the Captor X. Plug your guitar into your amp. Turn it on. You should have sound but if you don't, on the Apollo Twin, click the Input button and select Mic 1. Adjust your levels. Now click the Preamp button to select Mic 2. Adjust your levels.
If you don't have sound and Guitar Rig isn't seeing your signal, open Guitar Rig outside of Logic and click File at the top left. Go to Audio and Midi Settings. Check that Audio Device is Universal Audio Thunderbolt. Click Routing. Check that Inputs is set to 1: Mic/Line/HiZ 1 and 2: Mic/Line 2. Check Outputs is set to 1: Mon L and 2: Mon R. Quit Guitar Rig and go back to Logic.
Choose Guitar Rig for your audio unit plug in. You should have sound. I like to use the Stereo of Guitar Rig as well as the Reverbs. They're quite good.