I had already come across Eyvind before reaching the Sjaleng outpost and completed his sleepwalking sequence.
Once in Sjaleng the guard tell me to look for the deserter, Eyvind, so I go back to his camp but he's not there anymore and can't complete the event.
I looked everywhere around the area, over the zip-line, on the road to the Sjaleng outpost but nothing.
I think it's a bug and I can't really can't complete the event, I guess it's a Rygjafylke's mystery too.
@vykyng666 Hey there! Would you be able to share a video clip of the behavior you are seeing during this world quest so I can provide it for the game team to review?
Thank you for providing this image SilentWolf1121! I have a few questions for you, and anyone else is experiencing this issue of not being able to find Eyvind:
@zaphityr I'm so sorry for the delay in getting back to you, but thank you for providing this detailed walkthrough of how this has occurred. I have forwarded everyone's provided information to the Game team. If more info is requested, or if I receive any updates I will be sure to post here. Thanks so much for your continued patience, and if you have any more to add please let me know and I will be sure to forward that up as well!
Also, if anyone else experiences this issue with Eyvind please provide your platform below so that I may add your information to the investigation.
Good day everyone! Thanks for all of your patience. I have heard back from the Game team with the following information. In short, this is not a defect in-game and is working as intended.
Speaking with the guard at Sjaleng Outpost is not a quest or part of the "Eyvind Sleepwalker World Event." It is dialogue that points Eivor in the direction of the world event. It is intended that no follow up dialogue occurs with the guard and Eyvind should appear in the camp on a horse or just standing around. If you finished the world event and Eyvind is not present in the camp, reloading the save or restarting the game should make him appear, but already at this point the world event is completed. There is no extra reward or Artifact related to travelling back to Sjaleng Outpost after the "Eyvind Sleepwalker World Event."
However, let me know if any of you have any further questions or concerns.
Hello there @Roger86Klotz! Welcome to the forums 
I'm sorry to hear that you've had trouble completing "The Dreamwalking Warrior." Thanks for taking the time to share your experience with us.
The explanation shared by @UbiKobold is one that was provided by the dedicated teams themselves after investigating the reports they'd previously received about this mystery. If you're having trouble with this quest still, it would be helpful to have a video demonstrating what you're encountering in-game. A video will also help us to check up on that missing mystery you've reported, and if this is indeed "The Dreamwalking Warrior."
Would you please be able to provide a video which shows the following:
I'd recommend uploading this video to a sharing platform, such as YouTube or Google Drive, as this will allow you to post a shareable link within this thread we can take a closer look at.
Thanks! 
Hello @ecocrash! Sorry to hear that this is still happening. Were you able to update to the latest version of the game? If you haven't yet, please update your game and then go through our troubleshooting guide here, and be sure to verify your game files. If these steps don't help, could you provide a video as requested by @Ubi-Borealis above? Thank you!
@angryhands Glad to hear that loading the earlier save helps!
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