WARNING: Do not delete noble sims, especially Simcalibur owner!

Thank you, that's good to know. But this does not bode well for the culling system. Players who evict noble Sims from houses and have them marked as Unplayed now risk their games glitching with this. 

I have a hard time believing that the devs would overlook something so obvious. Has EA started heavily using AI lately? With the avalanche of bugs we are constantly getting, it sure seems like it. 

AND, I just discovered something else when the owner of Simcalibur is deleted: The heir can take the throne, but if no heir was chosen, then the next Arch Duke noble is told that the title is exclusive and that they cannot advance, so from then on, NO KING in the game!

I've also encountered this issue. I simply wanted to remove the preset royal families and build my own ideal royal dynasty from scratch—something I believe is a common and fundamental desire in a game like this. But apparently, that's not possible. It seems I'm forced to follow the path laid out by the game designers, which completely goes against the core philosophy of The Sims. I'm really disappointed.

It is disappointing. I never play the EA sims unless they have been revamped extensively, and frequently it is easier to simply delete and replace with my own sims. In a legacy/dynasty situation the natural thing for many people is to clear a game so the world/worlds have maximum space for favorite sims.

I have not tried yet to substitute the nobles in CAS with my own version of them with the same name, nor have I tried to rename or significantly alter the EA sims in CAS. That is on my list of tests to perform to see how it affects the crown menu and also the family tree. But this dynamic has certainly complicated things. 

Update: I was able to rename a noble sim in CAS without it causing a problem. I was able to change a noble sim's facial characteristics and alter the noble sim's body without it causing a problem. I was NOT able to substitute a noble sim by changing the name of the substitute to the name of the original noble sim and delete the original noble sim (that resulted in a missing sim, but it did not put a llamacorn placeholder in the crown menu).

I discovered that evicting the sim family removed their names from the crown menu without a llamacorn placeholder. But the game is still tracking them into a new world if they are moved.

I did discover a "fix" for the noble problem. Have every noble sim abdicate: they become non-nobles. Their names are removed from the crown menu. (And because they are no longer nobles, I am guessing they can then be deleted like any other non-noble sim in the game. But I do not know what it will do to family trees or a dynasty if they are deleted as non-nobles. That is a separate issue I did not test, as yet.)

I found the same problem. The only way to remove noble sims is evict household so sims are not in any world, then delete the household. I find that noble sims are tied with the world they currently live in which results appearance in kingdom manger on Manage World. 

I have already tried with the sims that Maxis made on the gallery. some of them are noble. One of them is the king. So if I place them in a world without a LV10 noble, then he will be the king right away. But if I placed it on a world that has a king, then he will be demoted to LV9.

I also tried out with the mid-level career as well where I made them (lv5, I guess) move to another world but they were demoted to lv4. So be careful with managing noble sims btw the worlds. I'm not sure if there's any guide in EA Help regarding this apart from managing dynasty and so on. 

Right now, I'm trying with another scenario where a noble parent lives in different world from the children. Because the children will get the title from noble parent and they will be appeared on the kingdom manager of the world of parent, not the world they live in. // for example, Noble parents are in Tomarang, but children are in Ondarion. In Kingdom manager of Tomarang, it will show the list of noble parent and their children while there's no show any of these sims in Ondarion. 

Hope this help!

Just take over the household and move them out. make a shack for them in newcrest. I did this and suffered no bad effects from doing so and was still able to become king of my own dynasty.