**User story**: As a Commons user, when I enter or submit structured data for a file, I want informative help text and error messages to aid me in the process both on the filepage and in Upload Wizard.
**We have this**: We're planning to make some incremental improvements to error handling through other tasks (T233051, T233052). Howeverwbparsevalue errors are displayed via MessageWidget above the offending input on add, there are a few remaining issues:which is exactly what we want and matches behavior of the filepage UI.
- UX between filepage and UW may be different, and unifying these experiences may be difficult due to differences in UIs
- T233051 requires a simple error message shown above the Publish button on the filepage. However, this may not be the best experience in some circumstances (long list of statements/qualifiers so that you can't see the offending field when clicking publish, uploading many images at once in UW)checks that run on submission of all data might be hidden if the user isn't viewing the offending file when they click the publish button.
**We want this**: An experience that makes errors easy to identify, understand, and fix both ondd a visual flag to the appropriate booklet page tab(s) to inform the user where the filepage and in UWpublish error(s) lies.
 Users can easily tell when an error occurs, which file(s) are affected, which field(s) caused it, and how to fix it.
During development, please test the following:
 Test this feature while logged in AND logged out
 Test this feature on at least one mobile browser
 Test that this feature works on the file page AND the Add Data step on UploadWizard (if applicable, some features only exist on one or the other)