Postby Emral » Sat Feb 22, 2020 9:48 am
1) Did you save when testing?
2) Does SMBX have write-permissions for the folder which the level file is located in?
If the answers to both of these are "yes" then I can't really give much advice other than "don't use the legacy editor it's really broken and buggy", sorry.
(*) Placing the warp should best be done at the bottom edge of the pipe, to make sure characters stay on the ground.