Backend error on login

Level:    FATAL
Errorcode:    E1027
Message:    PHP E_ERROR: Uncaught PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'login' cannot be null in /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Statement/Pdo.php:228
Domain:    core
Version:    not defined yet
File (Line):    /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Statement/Pdo.php (235)
Request:    GET https://xxxx.transline.de/editor/taskid/11988/?sessionToken=8dce4e8e71db4d277d0f043eed476671
Trace:Stack trace:
#0 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Statement/Pdo.php(228): PDOStatement->execute()
#1 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Statement.php(303): Zend_Db_Statement_Pdo->_execute()
#2 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Adapter/Abstract.php(480): Zend_Db_Statement->execute()
#3 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Adapter/Pdo/Abstract.php(254): Zend_Db_Adapter_Abstract->query()
#4 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Adapter/Abstract.php(577): Zend_Db_Adapter_Pdo_Abstract->query()
#5 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Table/Abstract.php(1076): Zend_Db_Adapter_Abstract->insert()
#6 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Table/Row/Abstract.php(469): Zend_Db_Table_Abstract->insert()
#7 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Table/Row/Abstract.php(440): Zend_Db_Table_Row_Abstract->_doInsert()
#8 /webs/instance-1021/library/ZfExtended/Models/Entity/Abstract.php(346): Zend_Db_Table_Row_Abstract->save()
#9 /webs/instance-1021/library/ZfExtended/Resource/Session.php(180): ZfExtended_Models_Entity_Abstract->save()
#10 /webs/instance-1021/library/ZfExtended/Resource/Session.php(109): ZfExtended_Resource_Session->handleSessionToken()
#11 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application/Bootstrap/BootstrapAbstract.php(687): ZfExtended_Resource_Session->init()
#12 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application/Bootstrap/BootstrapAbstract.php(630): Zend_Application_Bootstrap_BootstrapAbstract->_executeResource()
#13 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application/Bootstrap/BootstrapAbstract.php(590): Zend_Application_Bootstrap_BootstrapAbstract->_bootstrap()
#14 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application.php(389): Zend_Application_Bootstrap_BootstrapAbstract->bootstrap()
#15 /webs/instance-1021/library/ZfExtended/BaseIndex.php(174): Zend_Application->bootstrap()
#16 /webs/instance-1021/public/index.php(35): ZfExtended_BaseIndex->startApplication()
#17 {main}Next Zend_Db_Statement_Exception: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'login' cannot be null, query was: INSERT INTO `Zf_login_log` (`created`, `login`, `userGuid`, `status`, `way`) VALUES (?, ?, ?, ?, ?) in /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Statement/Pdo.php:235
Stack trace:
#0 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Statement.php(303): Zend_Db_Statement_Pdo->_execute()
#1 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Adapter/Abstract.php(480): Zend_Db_Statement->execute()
#2 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Adapter/Pdo/Abstract.php(254): Zend_Db_Adapter_Abstract->query()
#3 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Adapter/Abstract.php(577): Zend_Db_Adapter_Pdo_Abstract->query()
#4 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Table/Abstract.php(1076): Zend_Db_Adapter_Abstract->insert()
#5 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Table/Row/Abstract.php(469): Zend_Db_Table_Abstract->insert()
#6 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Db/Table/Row/Abstract.php(440): Zend_Db_Table_Row_Abstract->_doInsert()
#7 /webs/instance-1021/library/ZfExtended/Models/Entity/Abstract.php(346): Zend_Db_Table_Row_Abstract->save()
#8 /webs/instance-1021/library/ZfExtended/Resource/Session.php(180): ZfExtended_Models_Entity_Abstract->save()
#9 /webs/instance-1021/library/ZfExtended/Resource/Session.php(109): ZfExtended_Resource_Session->handleSessionToken()
#10 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application/Bootstrap/BootstrapAbstract.php(687): ZfExtended_Resource_Session->init()
#11 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application/Bootstrap/BootstrapAbstract.php(630): Zend_Application_Bootstrap_BootstrapAbstract->_executeResource()
#12 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application/Bootstrap/BootstrapAbstract.php(590): Zend_Application_Bootstrap_BootstrapAbstract->_bootstrap()
#13 /webs/instance-1021/vendor/shardj/zf1-future/library/Zend/Application.php(389): Zend_Application_Bootstrap_BootstrapAbstract->bootstrap()
#14 /webs/instance-1021/library/ZfExtended/BaseIndex.php(174): Zend_Application->bootstrap()
#15 /webs/instance-1021/public/index.php(35): ZfExtended_BaseIndex->startApplication()
#16 {main}
  thrown