Hi Willy,
There are at least a couple of problems.
Dimensions@system1
(* 24 *)
but there are 23 equations. The problem is that equation13 is repeated in the system1 list.
C = Inverse[A];
(* Set::wrsym: Symbol C is Protected. *)
The symbol C is a built-in WL symbol. All WL built-in symbols start with an uppercase letter, so avoid using symbol names that start with an uppercase letter. Use c instead.
