Small, but annoying: public constructors in abstract classes. The creation of abstract class is forbidden, why do they allow public keyword for the constructor of abstract class? It confuses the developer who reads. I`d require protected/private keyword only.

Dear CodeProject developers! I was editing the article (http://www.codeproject.com/Articles/321233/TMAverage) and I`ve received "The filename did not contain valid characters" when pressed Submit button. I didn`t find any problems about filename, so, I tried again - nothing changed. Then I posted another article with slightly changed names (directory name, article name). After editing and posting from one attempt I succeeded in publishing. But then, when I tried updating - got the same mistake: incvalid character in the filename. I think it`s not invalid character. The problem was also in incorrect view of the code (that`s why I decided to update) - but in the preview window it was just OK. Any ideas?