MediaWiki:Translate-checks-pagename/en

In what cases have you seen this error and was not able to understand its meaning? I ask because the error may appear for very different reasons and there is at least one bug with page translation.

You can see some examples here. Basically this message is shown to translations, where must the namespace part of a message be the same as original (english) one and not translated. Messages marked with this error are listed in untranslated and outdated lists, until the namespace part of the translation is not the same as original (english). But the message is not saying that, at least not for less experienced english speakers (like me). As you can see in that linked discussion, I tried first to find out, what am I supposed to do with the translation in order to hide that error message and just spanish translation helped to understand, what is purpose of this message.

What it means is that the namespace of the message (in this case "Help") should stay the same in translations. It was translated as "Nápověda:Odkazy" when it should be "Help:Odkazy". (Ideally, I guess it should be {{ns:Help}}:Okazy, though.) I do agree that the message needs better wording to make this clear though, but I don't have any good suggestions on how to improve it at the moment.