Sorry if there is already any similar bug reported...
NSIS Version: 2.46
There is a problem using 3 lines title and the reboot selection on finishpage....
to correct this problem change line 336 in file: ${NSISDIR}\Contrib\Modern UI 2\Pages\Finish.nsh
it is:
${NSD_CreateLabel} 120u 45u 195u ${MUI_FINISHPAGE_TEXT_HEIGHT_BUTTONS}u "${MUI_FINISHPAGE_TEXT_REBOOT}"
45u is a fix value... but this value isn't correct if 3lints for title is activated the value should be bigger ... so i came up to following solution..
${NSD_CreateLabel} 120u ${MUI_FINISHPAGE_TEXT_TOP}u 195u ${MUI_FINISHPAGE_TEXT_HEIGHT_BUTTONS}u "${MUI_FINISHPAGE_TEXT_REBOOT}"
hope i could help
including screenshots and sample
The MUI_WELCOMEPAGE_TITLE_3LINES option does exactly what you want.