Valid initData to Build Channel Parfor Error

I'm running into the following error inside of a parfor loop:

"Must have valid initData to build channel."

It appears to be linked to when I have a matrix that is retrieved to set loop-specific variables (Ex: a1 = LargeMatrix(:,c)). The size of the matrix is 30x205727. Is this too large of a variable to be transferred for a parfor loop or is there a better way I should be referencing it to avoid this issue?

Thanks!