Question The collider was not successfully "false" under the code

I am a student learning unity and would like to make a Proximity Driven Doors. The tutorial I am following is a video on YouTube at the following URL

if anyone is also interested is best. We can probably discuss it because I always making mistakes from start to finish

My problem is that the collider will let me pass when I try to get close to this collider, if not in this range the collider will not allow me to pass.

The code is as follows

The following warning appears (I don't really understand what the console warning means.)



Full details are as follows

My teacher told me to ask on the forum. Help me please. Also since I'm not a native English speaker, I hope there are no wording errors for everyone to understand!