Unable to start seafile server

Unable to start seafile server getting following error:
** Message: seafile-controller.c(1142): loading seafdav config from /opt/seafile/conf/seafdav.conf

failed to run “ccnet-server -t”

Hi sea_h,
welcome to the Seafile Community Forum!
You problem sounds like a permission problem. I guess you ran Seafile as root at one point. Please check file ownership and permissions.
If that doesn’t help, please provide a little more info about when the problem emerged. Help the community to help you!

seafile directory is owned by seafile user. and service able to initiate with seafile user but doesn’t starts.
it always gives same error: failed to run “ccnet-server -t”. while db service and nginx service run fine.

What about the subdirectories?