I have a large symmetric square 15x15 matrix (say B). With all entries in the region 0.285746383 and I am trying to calculate the eigenvalues of them using

with(LinearAlgrebra);
Eigenvalues(B);

B was originally an array that I converted to a Matrix with convert(B,Matrix).
I have also used type(B,Matrix) which returns true.

Yet when I enter Eigenvalues(B); It returns "Error, invalid input: LinearAlgebra:-Eigenvalues uses a 1st argument, A, which is missing"