You have probably set the collission wrong. Go to the database, go to tilesets find the tile you are using for your wall and click on it until it shows an x. I might be wrong since i´m using mv instead of mz, but im pretty sure this is the same across the two versions.
Hi regarding the 32 bit -> 64 bit
I am running on a 64 bit windows OS and tried doing this conversion. I converted all of the .exe files that I could find in the KADOKAWA\RPGMV folder using the 4gbpatch.exe file. However, after trying to access RPG Maker MV after this conversion, it simply will not load. Do you have any advice or any ideas?