Like for many other users, ever since JavaFX 8, I have encountered the error "Outstanding resource locks detected" whenever I use a WebView which plays an embedded MP4 Video.
Having seen that the issue was closed in https://javafx-jira.kenai.com/browse/RT-36386?focusedCommentId=460368&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-460532, I've checked with the latest beta version (jdk-8u60-ea-bin-b16-windows-i586-19_may_2015.exe) hoping that it would be solved in it, but unfortunately, the error persists.

Outstanding resource locks detected:
D3D Vram Pool: 13,243,584 used (2.5%), 67,108,864 target (12.5%), 536,870,912 max
11 total resources being managed
average resource age is 0.7 frames
0 resources at maximum supported age (0.0%)
3 resources marked permanent (27.3%)
3 resources have had mismatched locks (27.3%)
3 resources locked (27.3%)
5 resources contain interesting data (45.5%)
0 resources disappeared (0.0%)