I have faced with the following error running my program using cvx in Matlab:

"

Error using .*

Disciplined convex programming error:

Invalid quadratic form(s): not a square.

Error in * (line 36)

z = feval( oper, x, y );

Error in HW3_b (line 298)

` L(rho(jj),jj)*V(jj) >= (P(rho(jj),jj))^2+(Q(rho(jj),jj))^2;`

"

L, V, P, and Q are variables. The original form of the constraint was an equation. To make it relaxed, I used the inequality form of the constraint, but I faced this error. I was wondering what the source of the error is and how I can solve it.