I've been getting this message repeatedly over the past few days. Generally once I receive this message (or shortly thereafter)skritter freezes up entirely. The problem is resolved temporarily if I go back to the study page and start again, but comes up again pretty quickly.

Is anybody else having this problem? Anyone have any suggestions or fixes?

Do you have a lot of lists in the "Adding Words From" section on the on the Study page?
Since you know a lot of characters, it may be spending a lot of time parsing through the lists you're studying trying to find new words you don't know yet.

I have three lists in the "Adding Words From" section on the Study page, but I've had three or more lists that I've been adding from for at least three or four months without any problems previously.

I had this problem when I changed the study settings on a big list with several sections. I had studied most of the words in the earlier sections, but to keep up with a class I told Skritter I wanted to start at section 7. Later, I told it to start at section 1, so I would catch the few words I hadn't seen yet. That's when it took Skritter quite long to find new words to add, because it apparently had to check every word over again to see if it needed to be added or not.

If you set each of the lists in turn to review-only and then try adding, does it work? I wonder if there's a problem with one of the words in one of the lists that's causing the failure. If we could narrow it down to a particular list, section, or even word, it'd be easier to debug it.

Actually, that's exactly what I tried and it did work. Of the three lists I was adding from, two of them are different Chinese Pod Label lists, and when I set one of them (Chinese Pod- Daily Life Intermediate) to review-only, I was able to add again no problem. If it's helpful, I was adding from section 3 in the aforementioned list when I first ran into the problem. I think the problem may be related to what Kai mentioned - that list has quite a bit of redundancy- but it's not just taking a long time to add, it's freezing entirely when I am adding from that list.

Chcked it out and didn't see anything wrong, although it's possible there is corrupt data somewhere I haven't yet found. I wonder if you can grab the rest of the un-added words in Section 3, put them into a new list, and see if that list has the same problem. If it does, try deleting the first one (姑夫) and then we'll know if it is gumming up the works.

http://www.skritter.com/vocab/listsect?list=689214228&sect=2

You could also set the Daily Life list to section 4, which also might skip past the problem word(s).