Note: groups.io will be down for maintenance this evening, starting at 2AM Pacific Time (9AM Thursday 10/17/2019 UTC), for up to two hours.
Re: Javaw.exe issues
To be honest I have never been able to get javaw.exe to work - I've tried WinXP, Win7, Eagle 7.7 and all versions of Eagle 8 to no avail!!
My workaround to visualise the Gcode path is to use UCCNC (a free demo version from CNCzone works fine) which has an excellent toolpath display. I also use UCCNC software with a UC100 controller to drive my router.