Your Rocket.Chat version: 0.20.0

I'm trying to have working AD authentication. I don't have problems with OpenLDAP integration as I've done it on 3 different instances, but on Active Directory I can't get it working.
I'm doing almost all defaults, but in the logs I get keep saying that user is not found.

Is there a way to run server in more verbose state to see what exact LDAP query is being used to ensure that if I will run it in parallel using ldapsearch it will give/not give me informations?

Where I can define Base DN for user search, maybe because of that I can't find any users?

I'm using exact same configuration in Redmine (ldap user/password, group assignment) and it's working there, not here.

but on Active Directory I can't get it working.
I'm doing almost all defaults, but in the logs I get keep saying that user is not found.

Maybe it would help if you show us your ldap settings.

Is there a way to run server in more verbose state to see what exact LDAP query is being used to ensure that if I will run it in parallel using ldapsearch it will give/not give me informations?

You could set 'Log Level' to '2 - Errors, Information and Debug'. This setting can be found at 'Administration' -> 'Logs'.

This is our working 'Custom Domain Search':

'Unique Identifier Field' is set to objectGUID.

@homberger thx for tip with logs. Now I see that LDAP finds my user properly, question is rather why it can't authenticate me.

I've used Your settings and I have still the same problem. User is found, but I can't authenticate.
I'm using below settings:

Domain Base:
dc=domain,dc=tld

Custom Domain Search:
{'filter': '(&(objectCategory=person)(objectclass=user)(sAMAccountName=#{username}))', 'scope': 'one', 'userDN': 'CN=LDAP Reader,OU=Service Accounts,OU=Users,OU=UK,OU=Departments,DC=domain,DC=ltd', 'password': 'XXxxXX'}

Username Field:
sAMAccountName

Unique Identifier Field:
objectGUID

Sync Data: yes
Sync User Avatar: yes

User Data Field Map:
{'name':'name', 'mail':'email'}

Default Domain: empty

Logs: https://gist.github.com/Grejeru/894d1e2e03dab26b3a6d

Ok, I've found the reason. I've setup Rocket Chat to manually approve new users. After disabling this everything worked as a charm.