Hello everyone. I'm in the Twisted Firestarter quest.
I've spoken to the dwarf and activated the quest, found the very first trail near his house, followed until the bridge and the boat. I tried to watch a gameplay on YT because I couldn't figure out how to solve the quest, then I saw that I should see something on the ground and a command (the 'A' button on the gamepad) to interact with the quest again. Unfortunately. I can't see anything but a simbol of a magnifing glass, but can't interact with anything. And, there's really nothing on the ground. What can I do? :/

I usually walk in circles hitting 'e' over and over. If that doesn't work, I look for other clues. There are a few clues before you get to the water, I don't know how picky it is about the order you examine them. You could try going to the other side of the bridge (on the same side of the water as you are now), to see if you can find where the trail picks up, and just continue from there.

I solved the rest of the quest trying to go over the bridge, but the problem still remains in the rest of the game. When something important should be shown as red with witcher senses, it just doesn't.