[Solved] can't add user to joomla

Hi!
I have some users with wrong usernames in moodle. I have updated joomdle and forbid wrong usernames (i'm talking about capital letters in username).
So after that from joomdle panel I can see that this usernames have moodle account and joomdle user.
After that I have changed username to correct from moodle administrator panel and tried add this user to joomla via joomdle panel, but I've got white screen of death.
In apache error log I see:
PHP Fatal error: Call to a member function hashPassword() on a non-object in /path_to_joomla_site/libraries/joomla/user/user.php on line 653, referer: orthomission.ru/administrator/index.php?...m_joomdle&view=users

I don't know what can be happening in your site, as I just tested migrating a user from Moodle to Joomla and it worked just fine.

I checked Joomla code to see where the error is coming from, and it is inside "Updating an existing user" block, so it seems your user already exists in Joomla. Check that you don't have a user with same email or username (even in different capitalization)

So I repeat "add user to joomla" and all working fine. It's very strange, but seems that joomla need some time to delete its user from database.
Thank you for helping.