Error in int.nf%%ncol(x) : non-numeric argument to binary operator

When I run this code, the error presented occurs:

plotInt(x = X_irf, y = y_irf, int = "PLS3-_RASGRP1+", 
        read.forest = read_forest)


Error in int.nf%%ncol(x) : non-numeric argument to binary operator

Thanks in advance if anyone knows how to run this plot successfully.