Steps to reproduce:

1. Switch to different language
2. Open dashboard and edit widget, f.e., Item history and make changes to have invalid configuration (have Show lines empty)
3. Check out widget preview in background

Result:
Text Widget is not fully configured is not translates. Text Please update configuration is translated.

Language files also doesn't include translation key for that text.

Expected:
Text should be translated and language file should contain translation key.