Check_MK failed to login via LDAP after updated to v2.0.0p12

I have updated my Check_MK to v2.0.0.0p12. Almost everything is working fine except the LDAP login. I am getting the message repeately:

[Wed Oct 13 15:45:16.747766 2021] [wsgi:error] [pid 367] [client] WARNING: yacc table file version is out of date, referer: http://myserver/sitename/check_mk/

Google said that it is related with pycparser package. However, after I uninstall and reinstall the package, the problem is still there.

It would be appreciated if you could help me fix the problem.
Thanks and regards,

I have found issues. It is because of that some of the LDAP servers are not responsing and timeout the whole process.
Please close the case.

This is not an issue tracker here but a public forum. You can mark your own answer as solution.