Hi Tuan, in order to successfully run the latest version of MSP without errors on PHP 7.4, I had to modify this file:
C:\xampp74\htdocs\dev\components\com_osmembership\helper\helper.php on line 4082
I changed line 4082 from
if ($query != '' && $query{0} != '#')
to
if ($query != '' && $query[0] != '#')
Cheers
Paul