==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.3.1
- Deployed with iRedMail Easy or the downloadable installer? downloadable
- Linux/BSD distribution name and version: CentOS 7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Thank you Zhang for a new version. I found some problems with it, so I post here so we can resolve this together.

Updating from 4.5 -> 4.6
I think that the python3-simplejson should be python36-simplejson:

No package python3-simplejson available.

The installer made an error because of missing library:

* Clean up.
Traceback (most recent call last):
  File "delete_sessions.py", line 16, in <module>
    from tools import ira_tool_lib
  File "/opt/www/iRedAdmin-Pro-LDAP-4.6/tools/../tools/ira_tool_lib.py", line 21, in <module>
    from libs import iredutils
  File "/opt/www/iRedAdmin-Pro-LDAP-4.6/tools/../libs/iredutils.py", line 17, in <module>
    import simplejson as json
ModuleNotFoundError: No module named 'simplejson'
* iRedAdmin has been successfully upgraded.

When starting service, this file is not existing, I had to do "ln -s rhel7.ini rhel.ini"

 uwsgi[13079]: realpath() of /opt/www/iredadmin/rc_scripts/uwsgi/rhel.ini failed: No such file or directory [core/utils.c line 3654]

But even after all the fixes I get "502 Bad Gateway" from Nginx, and nothing special in the error log of iRedAdmin.

I can debug further, but have no idea where to start with iRedAdmin-Pro.

Thank you for your help!
Tom