I have windows 7 pro 64 bit as host, linux mint 18.2 64 bit as guest, firefox version 57.0 (up to date)
If I only use terminal or package manager etc built in tools, the guest runs nearly perfect, but if I launch firefox, then the guest system is almost doomed to crash sooner or later. This is just my observation and feeling and I don't know what information I should submit to you for scrutinizing. Please let me know and I will prepare it.