lightdm-session error message after removal of lightdm
 

I have Debian-9 stable running well with LXDE desktop. To change display manager, I installed 'lxdm' and removed 'lightdm'. The lxdm login screen appears properly, but on logging in I get an error message similar to following:

On pressing OK, the LXDE desktop starts properly and there is no further problem.

Why is this error coming and how can I get rid of it. I tried re-installing lxdm but the error is persisting. Thanks for your help.

the exact/full error message, and where and how and when do you get it?

with this info, i'd say it has something to do with x-session.

maybe update-alternatives can help?

The exact message was:

I found that "lightdm-xsession" was present in ~/.dmrc file. I deleted this file and uncommented following in /etc/lxdm/lxdm.conf

This seems to have solved the problem. Now xsession is not trying to launch lighdm-xsession and LXDE is starting immediately on logging.

Which package creates .dmrc? This file is not removed or corrected even after purging lightdm package.

yes, that happens regularly for files created by the program.