When OpenGL rendering is enabled, the [X] close button in the menubar (that is there when only one LibreOffice window is visible) is empty.
Jan Holesovsky committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=6f1184dfc0ec6dd1fd24b284737a68b05ffbb61c tdf#93892: Un-share maUserBuffer when the BitmapWriteAccess is requested. It will be available in 5.1.0. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Jan Holesovsky committed a patch related to this issue. It has been pushed to "libreoffice-5-0": http://cgit.freedesktop.org/libreoffice/core/commit/?id=90bbc7eacfa160c44a83fafbd11db12c28490879&h=libreoffice-5-0 tdf#93892: Un-share maUserBuffer when the BitmapWriteAccess is requested. It will be available in 5.0.2. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Fixed now.