Anytime I try to go to an event or create something I get a prompt that says I need an app?

[FlySoulo]

Anytime I try to create something or go to an event I get a prompt that says "an app must be downloaded" but then a prompt shows saying that "there's no app available?  Any solution for this?

[Freya Mokusei]

No idea, there's no useful information in your question.

You should update/edit it to include the browser and operating system that you're using - as well as the viewer name and version. For thoroughness, it might have value to paste the information from the Help > About menu from your viewer into your question.

You should also paste or copy the error message you're seeing exactly, word-for-word.

It's probably also necessary to explain what you're trying to do, or how. Parts of your question sound like you're in-world? But no 'app' required to create things in-world. This is not a generic Second Life error message in any way.