Thanks @DrewSSP, your posts did help me a lot in understanding the problem. More or less I’ll say the same things you wrote already again, but looking at the exact scripts was very helpful for me so I’ll still share.
So, the problem is that Memrise doesn’t accesses the database while “choosing” the wrong answers in multiple choice questions. Instead it generates wrong answers at a point (when you first start doing the course??) and adds them as some kind of “tags” to the word. And it won’t change those once generates tags when you change items in your database.
You can see the connected wrong answers for an item in the script that opens with the “ID-link” DrewSSP offered, for example http://www.memrise.com/api/thing/get/?thing_id=128626621:
Connected wrong answers in the script
Only words in that list did show up for real:
So, we have to force Memrise to redo the tagging. And the solution of DrewSSP with adding a letter and deleting it again in all text-columns works for me. It’s important you do this in all text-columns, doing it just in one column isn’t enough (I did this mistake first).
I’ve also realized that adding the new letter does the trick, you don’t necessarily have to delete it again.
Script after adding “X” in both columns
So, if you want to do the “manual” solution and if it’s only a private course you may just add a point after every item and leave it there. Doesn’t really disturb you while learning and saves you the time for deleting an added letter again.
Sadly, I don’t know enough about programming for using the script. So, I’ll do the point-adding manually now. But I’m still happy I found a solution even if this will take some time, but still muuuuch better than creating the whole course again or having a course with 90% old uncorrected answers as I added something to every word in one column which never showed up.
And maybe someone finds another solution to “force” Memrise to update the tagged wrong answers without the script or adding a sign to the existing columns. I already tried a bit like adding another text column and writing “x” in it or adding “x” as alternative answer, but sadly this didn’t make Memrise redo the connected wrong words.