Panel Unit Root Tests-Choi Test

[rehmansargodha]

Hellow

Can any one guide why the following message appear in PP-Choi test

Method Statistic Prob.**
PP - Fisher Chi-square 0.00942 1.0000
PP - Choi Z-stat NA

Test statistic value of 'NA' due to the present of a p-value of
one or zero

Thanks

Rehman