as it happened to many people there i also had problems with attributes.
I first lost attributes variation which showed as Pa_xxx; I solved it by going to each products backend page then Attributes>save attributes: all variations were back as before.
However 3 or 4 attributes text disappeared from ALL products, there are still showing in backend but are not showing frontend.
Any idea how to solve this?
PS: I di the modification to the two files JS cookies AND added the code to the theme php files, it didn't bring back any of the lost data frontend.