Validation Error Template

Hi, i've made my own datagrid and i can't figure it out where is the Validation adornment that make my design this way ... The goal is to only display the adornment on the textblock (Length in this case) which has an error when the value in negative. The error is in the Property so i assume the whole row notice it and that why the adornment is like this but i can't find the element which is doing this weird display. I've try to set ErrorTemplate to null but even that don't work. I've probably missed something but i can't find what. If someone can help me to fixed that it would be awesome. https://paste.mod.gg/mnvprormkcva/0

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