As I mentioned in the title, I transferred the builds I made from the blender to the studio, but I cannot approach some places. What is the reason?
This may be an issue with hitboxes. I suggest you get this plugin and use the “Show Decomposition Geometry” tool.
It should look something like this and will give you an overview of the hitboxes/tris.
I also highly recommend to not make entire structures in Blender. Blender is useful for assets and certain aspects of the map.
Would it be the same problem if I build in a roblox studio and texture it in a blender?
Most likely, as you’re importing the build into blender it will convert into an .obj file, therefore classifying it as a MeshPart when imported back into Studio.
Enable PreciseConvexDecomposition in the CollisionFidelity property.