I am new to Blender 3d,i try to use boolean modifier to cut model,but a un except error happened there is a circle on the "ExampleR", why after i use the boolean modifier,the "ExampleR" disappear? if i use "exact" instead of "fast",it works but it take a long time
the error example can be got here https://gofile.io/d/wCphqq
the selected verts is where the curve intersects with the model