To load a modified world, place the WLD and TWLD files in Terraria's Worlds directory. The TWLD file holds the modded data. Open Terraria and load the world. The TWLD file associates with the WLD file...
To load a modified world, place the WLD and TWLD files in Terraria’s Worlds directory. The TWLD file holds the modded data. Open Terraria and load the world. The TWLD file associates with the WLD file. If the TWLD file overwrites, try the recycling bin for WLD backups. Grab the WLD, TWLD, PLR and TPLR files to recover a lost world. The “t” extensions contain modded data. Double check loaded mods match enabled mods. The TWLD header lists last played mods. The TWLD header also stores original mods. File extensions indicate format. Match extensions, signatures and formats to open files. Analyze files to determine formats if issues occur.
Terraria