@Ghaunadaur, i thought it would be the navmesh ya, since its the only thing that say npc's where to walk and where not... and ya i checked them for errors and i got the mssg no errors.
The doors, hmm strange thing is, i dont get that mssg, just my hubby get it. We are both massive mod users , means our skyrims have both some gb's... we have around 80 mods on each... modding by myself now will reduce them a bit i think... but first i need to learn how, thats why im here and doing my lessons. The idea that he may get the mssg cause of one of his mods or otherwise i dont get it cause i dont have the same one or another one from me block that mssg... if that much mods installed its too difficult to see where is the reason for that.... True is and that is at least tested out... we walked in now with followers with us... they come in with us, in the house and in the basement, so the teleport itself is functionell for followers... But the followers stay then in place and dont move. Means we tested now with 2 different pc's and different followers + different installed mods.... He get the mssg, i not, but the behavior of our both followers in the house is the same.
Arion had some ideas i just tested out and checked: First my Final-Triangles may not enough under the doorteleportmarkers. Changed, made em bigger so most place used by the markers stay now in a finalized triangel... before i made the final navmesh again, i tested em with no errors. Test ingame: Followers enter still house and basement, seems it work a little bit better now, followers where following me from 1st floor to 2nd floor, but not in 3rd floor still. Basement, after enter it, followers didnt moved far, just a little bit, Vilja is following more than other followers (cerwidens follower behavior is not that much scripted as vilja, i would call it normal, and my hubby tested with Vilja and Lydia). But at last Vilja dont follow me in the 2nd room in the Basement which is just done with a house divider without a real door.
Next thing, Arion asked me if i may have an older version skyrim and or ck... Version of both: 1.9.32.0 means newest.
DarkRider asked me if i changed anything on the meshes after Finalizing... and well first time, no i didnt changed anything after, but as i deleted em to make em big enoug for place them better under the doormarkers... this time i changed after Finalizing... changed again, means deleted all final triangels again, made em new, checked with no errors, made finalizing em and this time no change after on em... Ingametest: no change from before.
Your idea about the doors so far, no script on em, i didnt copied em from anywhere, i just made em in from ck, normal solitude house doors, loading doors for sure.
Intresting Way to collecting ideas . When i do a house later i may use that block follower script on my bedroom door .
Greets
BlueBeast