Hi,
I have moved an existing OsTicket DB from an old server (osTicket v15.8) to a brand new server with fresh installation of Ubuntu 20.04, osTicket 1.16.3, PHP v8.0.20 and Apache/2.4.54. The database was exported and imported successfully into the new server.
I found the following issues in the new system.
- The Add New button does not respond when I tried to create a ticket on behalf of a user.

1a. The user list is not displayed when I click Add New button.
- 'Add Collaborator' button is not working.

The Advance button in the search option is not working.
Administrator options like Manage Account, Add User, Delete User, Import option and Send Password Reset email are not responding.

No errors in mysql.log / apache logs or syslog.
Can you please help diagnose the issue?
Regards,
Arao