TypeError after adding a few assets

• Type: Bug
• Status: Closed
• Resolution: Won't Fix
• Affects Version/s: Master
• Fix Version/s: None
• Component/s: ~ [Archived] Frontend Infrastructure
• Labels:
  • 7.1-could
• Fix Priority: 3
• Browsers:
  Firefox 52 ESR

Steps to reproduce:

1. Open a clean Firefox browser
2. Add 3 Web Content Articles or Blogs in quick succession

Result: CSS breaks and the following error happens

TypeError: inputPlaceholder is null

Reproduced on:
Tomcat 9.0.6 + MySQL 5.7.22
Portal Master Git SHA: 230f42bd85188e5c3fffa8b25345f63e13946f4a