Using Tall arrays in preparets

So im trying to do ome trianing using NARX on a rather large data set.... its in a cell array but I am unable to load all the data into preparets...... so Im trying to use tall arrays i guess..... not sure how to go about loading in my data

Error using preparets (line 102)
Inputs is not a matrix or cell array.

Error in gen_nn (line 83)
[x,xi,ai,t] = preparets(net_test,tall(trunc_TFinal),{},tall(trunc_Close));

[Jyotsna Talluri]

Can you share your dataset??