The CurseForge Client detects your addons and mods for you, and most of the time all you have to do is update and launch and enjoy your modded game.
However, there are some UI indications that we added to notify you when a specific project of file are of an unusual status.

These are visually represented with a small triangle sign with an exclamation point (!) in them. Hovering over the sign will show a tool tip with the specific information why this project/file was marked.

In this article we will cover these special cases and explain what they indicate, as well as of the implications for you.

Archived Files

Archiving files is a way for authors to remove their files from general view. Archived files are no longer searchable and will not appear when you browse in the client or website.
However, if you already have this project/file installed or if you gained access to it in other ways, our client will display it for you with the following indication:

In some cases you will still be able to update from your archived file version to the most recent version, in which case the 'Update' action button will be available, but further updates should not be expected unless the author removes it from from 'Archived' status.

In Minecraft - Archived Files are indicated in the modpack or profile page, mod page and modlist browsing when adding more content (once again with or without the option to update to the most recent available archived file)

You can read more about File statuses here.