Here is definitive Publishing troubleshooting guide that touches all the layers participating in publishing process.
In general, there are two categories:
No content changes were promoted to publishing target database/tables. This is the way to investigate why something was not published.
Content changes remain in cache due to Event Queue processing lag ...
Sitecore provides a cleanup agent to clear older media files, which clears media files every specified interval of time. By default it clears all media cache files created 90 days ago. See below settings in sitecore.config:
<agent type="Sitecore.Tasks.CleanupAgent" method="Run" interval="06:00:00">
<!-- Specifies ...
I've got a few articles for you to align on the publishing functionality:
How does the publishing work (in technical terms)
Typical reasons why smth is not published
From the message, it sounds like one of the items may have old/obsolete publishable to date left in the self-or-parent hierarchy.
I'd recommend inspecting selecting Standard fields , ...