aaPanel_Kern Thanks for your rapid reply. I've executed the command "bt 14", it returned as following:
aaPanel default info!
aaPanel Internet Address: https://...85:17900/9d
aaPanel Internal Address: https://...87:17900/9****d
Traceback (most recent call last):
File "/www/server/panel/tools.py", line 709, in <module>
File "/www/server/panel/tools.py", line 417, in set_panel_username
print('username: ' + username)
TypeError: can only concatenate str (not "NoneType") to str
If you cannot access the panel,
release the following port (7800|888|80|443|20|21) in the security group
I didn't change the port setting in security group recently, I am confused why it is suddenly unaccessable.