read-dump command

Dear all,
Hi, I hope you are well.
I try to use the read-dump command. After reading this command why don’t I have any pxx, pyy and pzz? I mean:

Step Lx Ly Lz Press Pxx Pyy Pzz PotEng Temp
0 83.988365 83.988365 83.988365 nan nan nan nan inf 0

Thanks in advance