teaser: prefill from article doesn't always work

[patte]

Bug Report

When trying to prefill a teaser from an article (von Artikel übernehmen) the frontend crashes.

I tried to reproduce the error on staging, but wasn't able. The bug was discovered in production.

• open the magazin front
• create "Teaser Tile Row"
• try to prefill the article: "Republik App"
• crash

I tried to mimic the "Republik App" article (discussion without lead and authors) and reproduce the bug on Linux/Chromium, but wasn't able.

Actual Results

Expected Results

The teaser get's prefilled with the aricles content.

Environment

• OS: OSX
• Browser: Safari 11