Looks like the Great Firewall or something like it is preventing you from completely loading www.skritter.com because it is hosted on Google App Engine, which is periodically blocked. Try instead our mirror:
This might also be caused by an internet filter, such as SafeEyes. If you have such a filter installed, try adding appspot.com to the list of allowed domains.
You are not adding any words from any vocab lists.
You don't have enough words selected to study (you need at least 4, and they can't share the same characters). You might also need to have automatic adding enabled, so that Skritter can get the list started. 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.) Look here for more information on this error.
Skritter is running slowly. If possible, please close other tabs and programs that might be using many resources, like Gmail or Outlook.
This is an experimental warning, so if it's popping up inappropriately, please let us know. We're always looking to make Skritter faster, so if it's running slowly for no reason, tell us about it so that we can improve. Click this popup to close it.