Steps to reproduce the issue:

1. Create two panels dashboard, one public, the other accessible for all users
2. Create a tabbed panel with the two precedents as content
3. Add it to a dashboard, accessible to public

Expected behavior:

• At edit time, to be warned of the incoherent state of the widget editing
• At view time, tabs with non accessible content inside should be skipped

Current behavior:

• At edit time, no warning
• At view time, inaccessible tab is visible and when opened prints (Invalid Panel) and breaks the bottom of the panel end's design doing so.