Using a map editor always carries a risk. Unlike paid software, free editors might not handle the new tile formats of Terraria 1.4.4+ perfectly. Here is how to avoid disaster:
Supports world files for current versions of Terraria (1.4.x). terraria map editor mobile free
No risk of mobile app crashes; most powerful tools available. 3. Terraria World Editor Web (Browser Based) Using a map editor always carries a risk