Here is some info. First stop all your trains that are working at their stations and delete their timetable. Then save. I downloaded editor from GitHub.com. When installed open your save file with the editor. Search for fgtrain. Then find the train that has mlsDocked checked. This will be your bugged train. Uncheck it and save. Load your game file in game and your train should be idle and ready to be deconstructed. NB: Ofc like all other editing backup your save file before any editing incase it goes wrong. I hope this helps people with similar problems.