Why I can mesh?

It said that ‘The tesselated surface is not closed. There could be a problem with the CAD geometry (such as self-intersections). Please inspect your geometry. Trying to proceed anyway.’.

Therefore, how can I fix it ?

Hi @clarahuang96!

In most of the cases you can ignore that message and can continue working on your project. Feel free to share your project link here and I will have a look at the model.

Best,

Jousef