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Published Sep. 10, 2025

LDAP settings and upgrading from 5.2.x to 6.x

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Liferay Support

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This article pertains to portals in which LDAP is configured in Liferay Portal 5.2.x and an upgrade is performed. When a user attempts to login, an error is thrown, and the user is not authenticated.

18:44:06,854 ERROR [LDAPAuth:321] Problem accessing LDAP server
java.lang.NullPointerException
at com.liferay.portal.kernel.io.unsync.UnsyncStringReader.<init>(UnsyncStringReader.java:34)
at com.liferay.portal.kernel.util.PropertiesUtil.load(PropertiesUtil.java:210)
at com.liferay.portal.kernel.util.PropertiesUtil.load(PropertiesUtil.java:203)
 

Resolution

The LDAP formatting in the database changed from 5.2.x to 6.x, and the stored values in the database remain as the old format, while Liferay Portal tries to read it as the new format when users attempt to log in. Among these formatting changes are new properties for LDAP that were implemented, as well as the multiple LDAP server settings.

The solution is to go to the Control Panel and edit the LDAP server and select "Save" on the server after verifying the settings are correct. This will resave the settings to the database in the proper format.
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