I can't add keyframes in the Graph Editor. It simply doesn't do anything after I hit "Only selected channels". It does add a keyframe when I hit "All Channels" but if I create another one, the first one gets deleted.
What could I try?
Is the Channel locked? look to the padlock Icon next to the channel.. Additionally what settings do you have ticked in user prefs > editing > Keyframing ?
I went back to the Keyframe Preferences lesson and saw that under Keyframing I had "Only insert needed" enabled. After disabling it, it worked. Thanks.
Another small problem: After I added the keyframes I don't see those small black squares like in the video. The KFs are there and I can select them just fine. It's just a bit hard to click on the right location.
I'm so sorry. That was just another stupid question. This time the problem was the theme I used (the CG Cookie) where the cubes where very small (at least on my 1440p monitor). I only saw them after zoomin into the screenshot.