A11y Screenreader: No Error Given for Invalid Entry: Logo Size Fields

Tested in version 1.0.1-SNAPSHOT-8db57a7

Using VoiceOver and Chrome/Safari

Description
Negative numbers available on Logo Size Height/Width Dropdowns. The

Steps

1. Access: local environment
2. Click 'Add New' button and select 'Metadata Provider’
3. Move through the application to page 3 User Interface / MDUI Information
4. Using screenreader/tab navigation, click down arrows on 'Logo Width' and 'Logo Height' dropdowns
5. Attempt to save page

What is occurring:
User has the ability to select '0' or a negative number. No error is provided through the screenreader why the page cannot be saved as they cannot locate the save button.

What is recommended:

It may be simpler to remove the ability to select negative numbers rather than having to add an error message. Either will resolve the issue.

Screenshot: VO_NoIndicationOfError4screenreader