Hi! I'm mantaining a server on forge 1.12.2 in mcprohosting and some new players are coming and I want to restore the world without removing some buildings I have done on creative like a supermarket, a bank etc... with custom npcs for trading etc... and I don't want to the this jobs again u.u
About the only way to do it that I know would be to download the world files, then open it in MC Edit and delete all the chunks that you don't want and then upload the new world save to the server. Since you're using forge, I presume the world is modded, and results in editing it with MC Edit might not be the best, some modded items might not be saved or transferred properly. I haven't used MC Edit in years, though, so it might have improved or there might be a new program out there that does the same thing.
You could also figure out what region files contain the structures you want to keep and just delete everything else. the problem with that is figuring out what region files are needed. I think there might be a way to translate the information from the F3 screen to do it, or it might tell you right there, I don't know.
Rollback Post to RevisionRollBack
To tell them how to live is to prevent them living.
You don't have to regenerate the chunks in MC Edit, just delete the ones you don't want and save the world file (make a backup) and load it onto the server. When the server loads and players join any missing chunks will be generated by the game, according to the current world seed and generation rules, along with any mods that change world generation, so if all that is still the same, the missing chunks should just regenerate and the existing ones should stay the same. That is, if everything goes OK.
The easiest way in MC Edit to delete chunks is to go to the top-down chunk view where you can select large areas of chunks and delete them all.