Extend the duration of the composition and the layers inside.
<aside> ⌨️ Modes:
Click Extend the duration of the composition and all nested ones by 2 seconds.
+ Alt(Option) Extend the duration of the current composition by 2 seconds.
+ Shift Enter the extended duration you wish in seconds.
</aside>
In some cases, after extending composition time, layers may become invisible in the viewer. This appears to be an After Effects caching bug. Despite the layers existing at the new time, they won't display correctly. If this happens, you'll need to clear the cache and possibly restart After Effects.