The complaints in the Google Maps Help forum are mounting (pun intended) where hikers are complaining that their user generated hiking maps no longer work due to a bug.
The bug basically takes the directions and routes labelled by these hikers in their My Maps, and snaps them to roads. The issue is, there are no roads or very few roads on mountains. If you snap those routes to roads, then the routes make no sense and are useless to hikers.
Making these routes is incredibly time consuming for hikers and to see them all changes overnight is worrisome.
Even when you uncheck the "Snap to Roads" feature it keeps the lines and routes snapped to the roads.
Googler, Daniel, came into the thread and said they are working on fixing it. She said:
Thanks for the reports. We are aware of the issue and are working to fix it as soon as possible. Your maps are not permanently changed and they will revert back to normal. ehg is right, you should avoid opening and editing your maps in the mean time.
I'll post again when I have updates on the issue.
Forum discussion at Google Maps Help.