HI Arthur DDevarth ,
When you say: "... in Blender 4.5, the “Limit Rotation” constraint no longer has the “Legacy Behavior” option."
What do you mean by that?

Also, as a side note, adding a timestamp to your questions is really helpful😉
Hello, Martin.
I don’t have the “Legacy Behavior” option in the Limit Rotation constraint. My Blender version is 4.5.4.
Yes, I disabled the rigging add-ons and restarted the program. Everything worked—thank you! I’ll continue with my training calmly.
What add-on is that DDevarth ?
I'd like to check it out.
I'm not sure if it would speed things up, but it's worth taking a look to see if it has potential.