I don't really have a clue how to reproduce it (and sorry if this is a duplicate, searching exact strings in JIRA seems impossible).
I started Minecraft, opened some other programms and pressed there F5 and suddenly Minecraft closed:
[18:30:28 INFO]: Launching game [18:30:28 INFO]: Unpacking natives to C:\Users\###\AppData\Roaming\.minecraft\versions\1.8.6\1.8.6-natives-25251689580656 [18:30:29 INFO]: Launching in ### [18:30:29 INFO]: Half command: ... (left that out) [18:30:29 INFO]: Looking for orphaned versions to clean up... [18:30:29 INFO]: Looking for old natives & assets to clean up... [18:39:20 ERROR]: Game ended with bad state (exit code 15) [18:39:20 INFO]: Ignoring visibility rule and showing launcher due to a game crash [18:39:20 INFO]: Deleting C:\Users\###\AppData\Roaming\.minecraft\versions\1.8.6\1.8.6-natives-25251689580656 [18:39:20 WARN]: Couldn't delete C:\Users\###\AppData\Roaming\.minecraft\versions\1.8.6\1.8.6-natives-25251689580656 - scheduling for deletion upon exit