Bevel sometimes fail

Hi, guys, someone knows why my Bevel don´t work sometimes. see this video. If is because of this gray faces, how can i resolve, thanks

  • spikeyxxx replied

    Looks like 'double Vertices' (and maybe some inconsistent Normals as well) to me; select all in Edit mode (with 'A') and then press M > Merge by Distance. And while you're at it: press SHIFT+N, to recalculate the Normals.