Hi there,
2 years later, this is still an issue
i had the same problems described above, the trick of "25ghosts" worked for me.
as an update anyway, on my system it was in a different location. it was in: machd/users/forallusers/avid/space
after changing the rights and applying to all folders, it finally worked.
drived me nuts, so thank you "25ghosts" for your help!