Hey, I had the same problem with one of my maps...I made a new one and it loaded up perfectly fine so I knew it was with the saved file...and looking at the first few lines of the error code you will see:
"java.lang.RuntimeException: Unknown character ' ' in 'C:/Users/RaZoR/AppData/Roaming/.technic/hexxit/saves/Adventure/mapwriter.cfg:1' "
Now I know nothing about the coding of this game and literally just tried a hell mary, but I opened up the file location of the mapwriter.cfg of the new world that loaded for me and copied the mapwriter.cfg then opened up the location of the world that wouldn't open and pasted it there, chosing to overwrite the existing mapwriter file. My world loaded up perfectly fine after this.
If you don't know how to get to the files:
1) open the start menu and type %appdata% and hit enter
2) open the .technic file
3) open the hexxit file
4) open saves file
Here you will find all of your worlds
5) open the 'new world' you are able to load and scroll down until you find mapwriter.cfg
6) copy it and back out of this world file
7) open your 'crashed world' and paste the file, overwriting the old one.
Like I said, I know nothing of the coding and it was a hell mary attempt that worked for me. Hope you have the same results
