This should be an optional string to be translated.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-28715 in the post.
| 0 | 
| Component | UE - Editor - UI Systems - Localization | 
|---|---|
| Target Fix | 4.13 | 
| Fix Commit | 2975559 | 
|---|---|
| Main Commit | 3050870 | 
| Created | Mar 24, 2016 | 
|---|---|
| Resolved | May 12, 2016 | 
| Updated | Jul 27, 2016 |