The thing is, you're creating a quest for another player (in the quest editor, the first player is [0], the second is [1], etc.).
1. **Quest Name.**
In the map editor, create ANOTHER (different from the previous one) name for the text document, click OK, and then write the quest name.
2. **Description.**
Create ANOTHER (different from the previous one) name for the text document, click OK, and then write the description.
3. False doesn't respond because of the error you described above.