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.
So I just got my computer back (Was posting stuff on my phone) But now my dang monitor's broken! I'll need to get a new one, which means... JOBS! Yaaay... When I get a new monitor, I'll post picture of one of my RPGMMV projects.
Wish me luck...
Had to clean up disk space because Windows Updates was having my primaries' disk space for breakfast, lunch and dinner. I guess the clean up thingy doesn't work or something because there were 15gigs of old update files in it.