[upload="error"]
The item's error message, hidden without one.
On this page
[upload="error"] is a template, read by file-uploader, file-input, configurator-file-input: it is never defined on its own.
Where it can go
- Inside
[upload="item"]. - Out of place, it stays in the page and does nothing.
What it requires
Nothing beyond Smootify: it works on every plan.