newbie asks about "LATCH primitive ... is permanently disabled"

A latch primitive is an asynchronous latch inferred from your code, something like

if a='1' then
  c <= b;
end if;

Disabled means, the condition a='1' does never occur in your code. Quartus is issuing a warning, cause it suspects, this behaviour may be unintentional. The warning is similar to a dead code warning from a C-compiler line xxx is never executed.

If you expect the condition to come true sometimes, you should check the code why it actually doesn't.