Peak amplitude to voulme Error

Hello,

I am using CopyPeakAmpToVol.lua script to convert peak amplitude to volume but I am getting this error mesaage:
.......
before loop PeakListName =NOE
[string "CopyPeakAmpToVol"]:58: attempt to call global 'TableSize' (a nil value)
.....

My peaklist shows the amplitude and all the assigned peaks.
Please let me know what is going wrong in here? Or, how to fix this issue?

Thank you very much,
Indrani