File .csv have 'nan' in colum

[5z3nn8v]

help me please i use
linux = Ubuntu 16.04
Cacti = 1.1.14

Time, i export file .csv
data = 'nan' in colum

i upload picture,

[RustedKnight]

what does the graph look like for this time slot?

[cigamit]

version 1.1.14 is over a year old and a ton of fixes (and 22 versions) have happened since then. You might try upgrading. Otherwise we would need to see output from the Cacti log, and the graph.