Is the word troll targeted by Yahoo not to post a question?

No, you can use the word. There must be another reason such as using the percent sign. It would help to know what happens when you try. Several things can happen:

1. If you take too long, you can lose the connection (type outside Yahoo and cut/paste to get around this)

2. You have exceeded your daily limit (does the word false appear?)

3. You exceeded the character limit (is the box red with a negative number?)

4. You have a bad cache file on your system, clean and reboot.

5. Just copy your question, refresh the page and paste it in again.

6. Certain links will cause problems, post without them and add as updates.

7. Symbols such as % will cause problems on mobiles. Spell it out.

8. On mobiles, try Desktop mode.

9. If it submits, but is not in the category, try this. Move to another category, count ten, then move it back again.

Sometimes when that happens, the question did submit, the problem is the next screen does not come up properly.