Parfor: discontiguous index error

Hi I am trying to process a batch of 250 tables using parfor and collect summary data from each. The names of the files are contained within Filelist. I have pre-allocated all output variables. Because of other problems with parfor I turned the contents of my loop into a function. This code works fine for small values of j (say 20) but for large numbers (say 100) returns the following error: 'Cannot create a table variable with a discontiguous index.' I'm not sure why. Index variables are within the bounds of the preallocated output table. I get that parfor randomly allocates loop variables but it's not clear why this should cause a discontiguous index problem. Even if it generates the following loop variables in a row [36,27,45,17], my understanding is that these should still be able to be used as column indices to insert columns into an output table of 100 columns without causing problems. Any assistance or a workaround would be much appreciated.

    NumT=array2table(zeros(size(Codes,1),size(Filelist,1))); %output array of collated T data
    TotalV=array2table(zeros(size(Codes,1),size(Filelist,1))); %output array of collated V data
    CurrentTCol=table(zeros(size(Codes,1),1));
    CurrentVCol=table(zeros(size(Codes,1),1));

    tic

parfor j=1:size(Filelist,1)
Filename=fullfile('C:\Users\etc\',string(Filelist{j,1}) );
[CurrentVCol,CurrentTCol]=CountTandV(Filename,Codes);
TotalV(:,j)=CurrentVCol(:,1); %insert current column into output array
NumT(:,j)=CurrentTCol(:,1);  %insert current column into output array
end
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