Iam trying to setup mailman3 on a shared webhost (with ssh access). I could use

pip3.6 install mailman --user

and also

mailman info

But when I try to start mailman using

mailman start

I will first get the error message

TypeError: expected str, bytes or os.PathLike object, not NoneType

and when I try it a second (and third etc.) time, it throws

Starting Mailman's master runner /usr/bin/python3.6: can't open file '/usr/bin/master': [Errno 2] No such file or directory

I didn't get any error messages during installation, so I guess whatever mailman is looking for in /user/bin/master is available in my /home/user/ folder, but I have no idea where and how to tell mailman to look there. For more infos, this is the output of mailman info

GNU Mailman 3.2.0 (La Villa Strangiato) Python 3.6.5 (default, Apr 10 2018, 17:08:37) [GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] config file: /var/www/virtual/user/html/var/etc/mailman.cfg db url: sqlite:////var/www/virtual/user/html/var/data/mailman.db devmode: DISABLED REST root url: http://localhost:8001/3.1/ REST credentials: restadmin:XXXX