As wrote in a post for a different question, I've started to use it with 4 words that are (still) a bit confusing to me: 以后 yǐhòu, 时候 shíhou, 以前 yǐqián, 时间 shíjiān.

I've pressed "Study starred words" and was asked to write one of them, then to recognize another one and afterwards got a following message:

You don't have enough words selected to study (you need at least 4, and they can't share the same characters). In order to get started practicing with Skritter, please go to the Vocabulary Lists page to choose what you'd like to study. (Or make sure you're studying the right language--you're in Chinese mode.)

Any help, please?

PS: Something feels inconsistent to me here: if the list I've created is wrong, then why can I "study" it at all? And the message is explaining what should happen, but why the limitation is so rigid? What's wrong in the list I've created after reading your post on Starred Words?

The error message says "and they can't share the same characters". It's a limitation of how the Flash client holds onto a character in a word and other words with that character can't be loaded until it's been both done and released (and it holds onto it for at least one word after, in case you want to go back).

This error is annoying, though, so we have it on our list to Do Something About It.

Ideally, you'd either have a couple more starred words in there, or do this practice on the scratchpad without progress tracking, which only needs two words minimum and they can share characters.

Yeah, sounds like a technical issue. Perhaps, adding some timestamp/rand to the character signature to distinguish between the instances might be a solution? :)

That way or another, you have much more expertize :)

Seems that my usage of starred words is kinda legitimate and follows the guidelines, so good to know (again) that it's on your to do list somewhere.

PS: and meanwhile if the starred words set is not "study-able", why can I press study and see the error later?

It's not smart enough to figure out what's going to happen in advance. That's part of what we would fix.

:)) Gotcha.
Thanks again