This inspection warns about nil-safe chained calls which could be replaced with safe navigation operator usage. A group of chained calls is likely to represent subsequent checks for nil in every call component, like:

if u && u.profile && u.profile.thumbnails && u.profile.thumbnails.large
  # do something...
end
This expression could be replaced with:

if u&.profile&.thumbnails&.large
  # do something...
end