Please help us help you and fill where relevant:
Your LimeSurvey version: LimeSurvey Community Edition Version 6.4.1+240108
Own server or LimeSurvey hosting: Own Server
Survey theme/template: default
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Hi,

I'm banging my head on the wall trying to get AuthLDAP to work, all I want is to allow our "Active Directory" users to authenticate to LimeSurvey using their Active Directory credentials. Our AD domain function level: Windows Server 2008 R2. This LimeSurvey installation is a fresh installation, and it's my first encounter with LimeSurvey. I have configured many other systems and applications to authenticate against our AD, but this one just will not work. 

The AuthLDAP documentation is very limited, and does not include explanation for all options.

Using the attached configuration, I always get: "Incorrect username and/or password!"

Is there something wrong with my configuration values?
How should the username should be typed, domain\samaccountname, samaccountname@domain.com, samaccountname  ?
What is the difference between "simple bind" and "Search and bind"?
Do we need to create LimeSurvey user for every AD user? I hope not!

Any help would be appreciated.

New AD disable no SSL access, try with ldaps://

You have some example : manual.limesurvey.org/Authentication_plugins#LDAP

Difference between simble bind and search and bind

- simple bind : Authentication on the LDAP are done using the username and password sent. If authentication are OK : login.
- Search and bind : use another user to search the user with this username. Check if password is OK after.

I have only a Search and bind for Active directory.