Symptoms
after upgrading to 4.6.9 "Umlaute" aren't rendered correctly. Take a look at the title bar of the sub view (Error Umlaute) and how it looks like on 4.6.7 (Umlaute before 4.6.9).
Please see attachments.
Diagnoses
The issue is reproducible by creating a subview with umlaute characters.
Resolution
There is a coldfix for this issue.