TYPO3 Core

Problem:
when updating translations with the extension manager the dynamic update of the progress bar and the display of messages during the update is broken.
The update of translations works - this affects only the output.
Reason for this is the output buffering/compression which is activated in init.php

Solution:
end output buffering by adding ob_end_flush();

affected versions: 4.2 and 4.3

(issue imported from #M11986)