I don't think this is the best solution, but it worked for my LazSerial's installation
If you don't need highest baudrates you can remove them: comment/remove these lines from synaser.pas
,(500000, B500000),
(576000, B576000),
(921600, B921600),
(1000000, B1000000),
(1152000, B1152000),
(1500000, B1500000),
(2000000, B2000000),
(2500000, B2500000),
(3000000, B3000000),
(3500000, B3500000),
(4000000, B4000000)
and change this
MaxRates = 30; //UNIX
to this
MaxRates = 19; //UNIX