Just the one tab, and I don’t use any scripts. I’m using firefox on a linux mint system, and once the same word came up in the review cycle again I was able to pass it normally.
Perhaps it was a weird one off, but it was still quite frustrating.
If it happens again, I would recommend refreshing the page so you don’t have to put a wrong answer in, but without more information I’m not sure the staff will be able to find a cause for that specific instance.
If this happens again for whatever reason, consider installing [Userscript]: Double-Check (Version 2.x). As long as you know you won’t abuse it, it can help with simple things like this.
Having a second window with reviews open or accidentally hitting the space bar before or after you input your answer for the reading question will cause wanikani to shake your answer.
I assume you accidentally had a space in there. If this happens, delete and make sure you see the light gray 答え in the answer box indicating that there is nothing in there.
I doubt this is a script or WK issue. As @seanblue and @sadfghjkl have already said, most likely there was simply an empty space at the beginning, and then WK won’t accept the answer.
Hi @Ararothea! WaniKani will shake without a message if there’s a space, as others have already mentioned, and also if there is romaji or kanji in the answer field. It doesn’t sound like romaji or kanji, though, so a space is the most likely explanation. Please let us know if this happens again and deleting and retyping doesn’t fix it. As seanblue mentioned, a screenshot or (even better!) a video would really help us to get to the bottom of it! Sorry for the frustration