How can I fix the non-conformable arguments error in my R code?

Question

x_bar = numeric(ncol(radio))
for(i in 1:ncol(radio)){
  x_bar[i] = mean(radio[,i])
}

covmat = function(x){
  n = ncol(x)
  A = matrix(dat = numeric(n^2), ncol = n, nrow = n)
  for(i in 1:n){
    for(j in 1:n){
      A[i,j] = cov(x[,i],x[,j])
    }
  }
  return(A)
}
S = covmat(radio);invS = solve(S)
m = nrow(radio)
di = numeric(m)
for(i in 1:m){
  di[i] = t(radio[i,]-x_bar)%*%invS%*%(radio[i,]-x_bar)
}

The code above is for calculating the 'mahalanobis distance' of the data 'radio' which is 98x6 dimensions.

whenever i run for(i in 1:m){di[i] = t(radio[i,]-x_bar)%*%invS%*%(radio[i,]-x_bar)} the program send me a error which says the vector calculation code is not available because of the vector dimension problem.

However, When I check the matrices(S, invS) and vectorsradio[1,]-x_bar, the matrices have rank 6 and dimension of the vectors are all 6. Please help me. thank you