Dear Michael,

You have to upgrade iRedMail from 0.9.0 to 0.9.1, 0.9.2, then 0.9.3. The upgrade tutorials are available here:
http://www.iredmail.org/docs/iredmail.releases.html

The iRedAdmin-Pro "internal server error" of License page is a bug, i will send you a patched version, and we will release a bugfix release soon. Sorry about this trouble.

You can try this command:

ls -l /opt/

Also, version number is stored in file /opt/iredapd/libs/__init__.py.

Any related log in Apache or uwsgi log file?

Please updated `policyd_enabled =` to False in iRedAdmin-Pro config file like below:

policyd_enabled = False

Then restart uwsgi service and try again.

ok i think i found it in /usr/share/apache2/iredadmin/settings.py

but even after changing to policyd_enabled=False i still have the 500 errors:

'module' object has no attribute 'iredapd_db_host'
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/web/application.py", line 239, in process
    return self.handle()
  File "/usr/lib/python2.7/dist-packages/web/application.py", line 230, in handle
    return self._delegate(fn, self.fvars, args)
  File "/usr/lib/python2.7/dist-packages/web/application.py", line 420, in _delegate
    return handle_class(cls)
  File "/usr/lib/python2.7/dist-packages/web/application.py", line 396, in handle_class
    return tocall(*args)
  File "/usr/share/apache2/iRedAdmin-Pro-SQL-2.2.0/libs/sqllib/decorators.py", line 26, in proxyfunc
    return func(*args, **kw)
  File "/usr/share/apache2/iRedAdmin-Pro-SQL-2.2.0/controllers/sql/domain.py", line 168, in GET
    qr = lib_greylist.get_greylist_setting_and_whitelists(account='@' + self.domain)
  File "/usr/share/apache2/iRedAdmin-Pro-SQL-2.2.0/libs/iredapd/greylist.py", line 9, in get_greylist_setting_and_whitelists
    gl = Greylisting()
  File "/usr/share/apache2/iRedAdmin-Pro-SQL-2.2.0/libs/iredapd/__init__.py", line 44, in __init__
    self.db.supports_multiple_insert = True
AttributeError: 'Greylisting' object has no attribute 'db'

************* [pid: 2535|app: 0|req: 6/7] 95.236.105.209 () {50 vars in 1209 bytes} [Mon Dec 21 15:14:25 2015] GET /iredadmin/profile/domain/general/************ => generated 21 bytes in 10 msecs (HTTP/1.1 500) 2 headers in 165 bytes (2 switches on core 0)

Wait a second but - i can not upgrade from the old iRedmail release to new iRedmail release?
The upgrade process from 0.9.0 to 0.9.3 is just to follow all the steps mentioned in the upgrade processes from each version to the next, there is nothing to download and upgrade, right?

i have done the change ti iRedAdmin-Pro config file as suggested - the error persists even after restarting the server.

but now trying to restart apache service gives

(98)Address already in use: AH00072: make_sock: could not bind to address [::]:8                                                                      0
(98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.                                                                      0:80
no listening sockets available, shutting down
AH00015: Unable to open logs
Action 'start' failed.
The Apache error log may have more information.
                                                                         [fail]

I have restarted the uwsgi service but i guess that would be restarted when rebooting the whole server anyway - and it doesn't help...
should i retry to upgrade iredadminpro?
it might be true that i tried to upgrade iredadminpro without upgrading iredmail and iredapd before... however i think i tried to run the upgrade again afterwards... it says success everywhere but somehow all doesn't help...

grep 'policyd_' settings.py gives:

policyd_enabled = False
policyd_db_host = "127.0.0.1"
policyd_db_port = "3306"
policyd_db_name = "cluebringer"
policyd_db_user = "cluebringer"
policyd_db_password = "**********************************"

grep 'iredapd_' settings.py gives:

iredapd_enabled = True

that did the trick! you are a true master of this!

Why don't you do all the upgrading also of iredmail and iredapd in this sort of script style? it would save a lot of time and effort...

thanks for your help!