Your answer resembles spam.
It was promoting a resource. It's a one-line answer which doesn't even provide any guidance on how to use that resource - there's a severe lack of effort to provide a useful answer here. There are, additionally, features already built into ASP.NET to deal with the problem, so an external resource isn't necessary.
For a long-term user, these factors together set off loud alarms that you might just be using this as an excuse to advertise a tangentially related resource, whilst putting in no effort to provide a genuinely useful answer.
How do you avoid getting your answer deleted in the future?
Next time you link to an external resource, make your answer actually a substantial answer. Put some effort into your response and actually provide guidance on using that resource. Sure, they can use this library - but how? What do they do with it? What features do they use? What is the library even for? What is it about? Why would they want to use this?
"Here, use this library" opens up more questions than it answers. If that is all your answer consists of, you're doing something wrong.