TYPO3 Core

Could you please check if it works with any other option? E.g. check if bookmarks are still enabled, when you enter this line:
options.enableBookmarks=0

I believe this is no problem with defaultUserTSconfig but only with the property "options.pageTree.showPageIdWithTitle". Is that right?

options.enableBookmarks=0
is set

The "Create bookmark on this page" icon is still there.

I just realized that you are speaking about the field for the frontend ([FE][defaultUserTSconfig]) while your option (and also the one I mentioned) belong to the backend.

There also is [BE][defaultUserTSconfig], which you should be able to set manually in localconf.php. Does that work?
Seems like this field is no longer shown in the Install Tool since #21321 (rev. 6357). But don't ask me why...

thank you for the hint.

Now I have this line in the localconf.php

$TYPO3_CONF_VARS['BE']['defaultUserTSconfig'] = 'options.enableBookmarks=0\' . LF . \'options.pageTree.showPageIdWithTitle = 1\' . LF . \'setup.override.navFrameResizable = true\' . LF . \'setup.override.navFrameWidth = 400\' . LF . \'setup.override.titleLen = 100';

but it does not work

localconf.php:
$TYPO3_CONF_VARS['BE']['defaultUserTSconfig'] .= '
options.pageTree.showPageIdWithTitle = 1
';

Works for me in 4.5 and before. Don't forget the .= (including dot) to append your config to already existing defaults from config_default.php, otherwise you for example unset the contextmenu config of the pagetree.