Cannot log into confluence due to IncorrectResultSizeDataAccessException

[Dastin_Kuwałek__SoftwarePlant_]

I have switched my Confluence instance from one LDAP connector to another one by adding the second connector, syncing it and then removing the old connector. It worked for 3 hours but then, suddenly the Confluence stopped showing the login form. Instead, every time a person wants to open the login page, it shows an oops error with this message:

Cause

org.apache.velocity.exception.MethodInvocationException: Invocation of method 'isShowSignUp' in class com.atlassian.confluence.user.actions.LoginAction threw exception java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.util.concurrent.CompletionException: org.springframework.dao.IncorrectResultSizeDataAccessException: query did not return a unique result: 3 at /login.vm[line 6, column 28]
    at org.apache.velocity.runtime.parser.node.ASTMethod.handleInvocationException(ASTMethod.java:337)

I have checked the login.vm file and line 6 looks like this:

#set($showSignup = $action.isShowSignUp())

 So the problem is with the invocation of the isShowSignUp() method but I don't understand why Confluence would find 3 results instead of one ...

How can I unlock this?

I was thinking about hardcoding a 'true' value to remove the call to the isShowSignUp() to prevent the database lookup.

I have checked the knowledge base about Confluence thrown a null pointer exception and fixing the order of connector in the database, but this is not my case.

All help will be appreciated! =)

Thanks in advance,

Dastin