For those who don't read the Steam Forum, Loki posted this fix for people who have two copies of the XP Grinder, one of which fails to get awarded at 500,000 XP...

 

Looks like your system never purged the old achievement after we fixed it, here is how you can clear out the legacy (duplicate) XP Grinder Achievement:

 

Exit Flight

Delete: 4D5308D2.gpd

Restart Flight

Thanks, just what I needed.

What's the location of this file, I can't find it.

What's the location of this file, I can't find it.

C:\Users\UserName\AppData\Local\Microsoft\XLive\Content\E00002**********\FFF*****\00010000\E00002**********_MountPt

 

Fred.