User cannot register in ojs 3.2.1.1

i have installed ojs 3.2.1.1 in my hosting. my problem is new user cannot register with my single hosted journal. my site https://difusiiptek.flipmas-legowo.org/difusi_iptek/user/register
i have tried many times. the register page just like refresh to blank form again after i clicked register button and don’t show any error message. and in error log don’t show any error just message like this:
[23-Sep-2020 11:39:41 Asia/Jakarta] PHP Warning: Creating default object from empty value in /home/flipmasl/public_html/difusiiptek/cache/t_compile/ecc55761ebbb35f58f8f534694562dbd01538725^52019e87b90081f2c6bfa717994d81ab7712dd1f_0.app.frontendcomponentssearchF.php on line 30
[23-Sep-2020 11:39:41 Asia/Jakarta] PHP Warning: Creating default object from empty value in /home/flipmasl/public_html/difusiiptek/cache/t_compile/ecc55761ebbb35f58f8f534694562dbd01538725^52019e87b90081f2c6bfa717994d81ab7712dd1f_0.app.frontendcomponentssearchF.php on line 30

i have changed configuration in confing.inc.php:
; Force SSL connections site-wide
force_ssl = On

; Force SSL connections for login only
force_login_ssl = On

; This check will invalidate a session if the user’s IP address changes.
; Enabling this option provides some amount of additional security, but may
; cause problems for users behind a proxy farm (e.g., AOL).
session_check_ip = Off

and the problem still exsist. can u help me?