Most tutorials show a clean run from start to finish. The viewer following along rarely gets one, and the gap between the two experiences is where instruction breaks down.
A clean run hides the decision points
Demonstrating the correct path shows what to do but not why that option was chosen over the alternatives sitting beside it.
Without that reasoning, the viewer is copying a sequence rather than learning a procedure. The instruction holds only while conditions match the recording exactly.
Failure cases expose the reasoning naturally. Showing what happens when the wrong option is selected makes the distinction concrete in a way a correct demonstration cannot.
Errors are how people confirm they are on track
A viewer who encounters an unexpected message has no way of knowing whether it is normal. The absence of that message from the tutorial suggests something has already gone wrong.
Most abandonment happens at exactly this moment. The task may be recoverable, but the viewer has lost confidence that the video still describes their situation.
Naming the common warnings and stating plainly which are harmless converts a moment of doubt into a confirmation that the process is proceeding as expected.
The recording process filters failures out
Creators usually rehearse a task before recording it, which means the recording is a second or third attempt. The problems encountered in the first attempt never reach the camera.
Those first-attempt problems are precisely the ones a newcomer will meet. The rehearsal that makes the video watchable also removes its most valuable content.
Keeping a note of every obstacle hit during preparation preserves that material, and it costs nothing beyond writing them down before they are forgotten.
Where failure content belongs in the edit
Interrupting the main sequence with every possible error makes a tutorial unfollowable. The successful path has to remain continuous and easy to keep pace with.
Brief inline notes work for errors that stop progress entirely, because a viewer stuck there cannot continue to a later section anyway.
Everything else fits better as a short segment after the walkthrough, where it can be found by anyone searching for a specific message without slowing the main run.
Comments are the missing failure list
The questions accumulating under an instructional video are a record of every place the instruction was insufficient, gathered from people who genuinely attempted the task.
Answering them individually helps one viewer at a time. Folding the recurring ones into the video, or into a follow-up, addresses everyone who will arrive afterwards.