I tried both with Internet Explorer and Chrome.
Tried 2 days in a row without success.
Other pages in the knowledge base works fine.
I have a feeling this may be a wider issue than that one particular article, as some other articles I've tried opening from the external (customer visible) view, are taking forever to finally open. The one you mentioned does present the error you specified though.
I'll try and report this internally, if it hasn't already been reported.
FYI, I can access the article internally, and I'll paste the contents here for you, so you can at least see it:
You may want to open a Support case, if you have questions around this.
Article contents below:
I haven't heard anything back officially, but this morning, I've tried viewing this article a few times, and it seems like it's now loading as it should, so perhaps they have fixed this now?