Spark 2.6.x and SSO

Hi, all.

After a couple of days I have working setup of Win2008r2 + OpenFire 3.8.2 + AD + SSO + Spark 2.5.8(on Win7x64).

Regarding to the following topics, Spark 2.6.x has "TGS-REQ" problems with SSO:

http://community.igniterealtime.org/message/231862#231862

http://community.igniterealtime.org/message/215762#215762

I've tried to install all Spark versions from 2.6.0 to 2.6.3.12555.

The problem exists everywhere.

Mechanism level: Server not found in Kerberosdatabase (7)

Any ideas about how to fix it, or when the developers will fix it?