After some time, API stopped work. 
When I try to run any request I see only "Internal Server Error" and the log like this: 

2015-11-18 17:53:05,634 ERROR [org.ovirt.engine.extension.aaa.jdbc.binding.api.AuthnExtension] (default task-314) [] Unexpected Exception invoking: AAA_AUTHN_AUTHENTICATE_CREDENTIALS[d9605c75-6b43-4b00-b32c-06bdfa80244c]

How can fix it?

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Maksim Naumov
Hitmeister GmbH 
Softwareentwickler

Habsburgerring 2
50674 Köln


HRB 59046, Amtsgericht Köln
Geschäftsführer: Dr. Gerald Schönbucher