Error-mysqlInnoDB: Error: "mysql". "innodb_table_stats

Attached error log: 2015-06-2322: 39: 061252 [Note] Giving0clientthreadsachancetodiegracefully2015-06-2322: 39: 061252 [Note] Shuttingdownslavethreads2015-06-2322: 39: 061252 [Note] Forcefullydisconnecting0remainingclients2015-06-2322: 39: 06... mysqlerror

Attached error log:

22:39:06 1252 [Note] Giving 0 client threads a chance to die gracefully
22:39:06 1252 [Note] Shutting down slave threads
22:39:06 1252 [Note] Forcefully disconnecting 0 remaining clients
22:39:06 1252 [Note] Binlog end
22:39:09 1252 [Note] Shutting down plugin 'Partition'
22:39:09 1252 [Note] Shutting down plugin 'blackhole'
22:39:09 1252 [Note] Shutting down plugin 'performance _ scheme'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ SYS_DATAFILES'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ SYS_TABLESPACES'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ sys_foreign_cols'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ sys_foreign'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ SYS_FIELDS'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ SYS_COLUMNS'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ sys_indexes'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ sys_tablestats'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ SYS_TABLES'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ FT_INDEX_TABLE'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ FT_INDEX_CACHE'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ FT_CONFIG'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ ft_being_deleted'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ ft_deleted'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ ft_default_stopword'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ Metrics'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ buffer_pool_stats'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ buffer_page_lru'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ BUFFER_PAGE'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ CMP_PER_INDEX_RESET'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ CMP_PER_INDEX'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ cmpmem_reset'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ CMPMEM'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ cmp_reset'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ CMP'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ LOCK_WAITS'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ locks'
22:39:09 1252 [Note] Shutting down plugin 'innodb _ trx'
22:39:09 1252 [Note] Shutting down plugin 'innodb'
22:39:09 1252 [Note] InnoDB: FTS optimize thread exiting.
22:39:09 1252 [Note] InnoDB: Starting shutdown...
22:39:12 1252 [Note] InnoDB: Shutdown completed; log sequence number 44832642
22:39:12 1252 [Note] Shutting down plugin 'Archive'
22:39:12 1252 [Note] Shutting down plugin 'myisam'
22:39:12 1252 [Note] Shutting down plugin 'csv'
22:39:12 1252 [Note] Shutting down plugin 'mrg _ myisam'
22:39:12 1252 [Note] Shutting down plugin 'Memory'
22:39:12 1252 [Note] Shutting down plugin 'sha256 _ password'
22:39:12 1252 [Note] Shutting down plugin 'MySQL _ old_password'
22:39:12 1252 [Note] Shutting down plugin 'MySQL _ native_password'
22:39:12 1252 [Note] Shutting down plugin 'binlog'
22:39:12 1252 [Note]/usr/sbin/mysqld: Shutdown complete

150623 22:39:12 mysqld_safe mysqld from pid file/var/run/mysqld. pid ended
150623 22:39:39 mysqld_safe Starting mysqld daemon with databases from/var/lib/mysql
22:39:39 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use -- explicit_defaults_for_timestamp server option (see documentation for more details ).
22:39:39 1190 [Warning] Buffered warning: Changed limits: max_open_files: 1024 (requested 5000)

22:39:39 1190 [Warning] Buffered warning: Changed limits: table_cache: 431 (requested 2000)

22:39:39 1190 [Note] Plugin 'Federated 'is disabled.
22:39:39 1190 [Note] InnoDB: Using atomics to ref count buffer pool pages
22:39:39 1190 [Note] InnoDB: The InnoDB memory heap is disabled
22:39:39 1190 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
22:39:39 1190 [Note] InnoDB: Memory barrier is not used
22:39:39 1190 [Note] InnoDB: Compressed tables use zlib 1.2.3
22:39:39 1190 [Note] InnoDB: Using Linux native AIO
22:39:39 1190 [Note] InnoDB: Not using CPU crc32 instructions
22:39:39 1190 [Note] InnoDB: Initializing buffer pool, size = 1.0G
22:39:40 1190 [Note] InnoDB: Completed initialization of buffer pool
22:39:40 1190 [Note] InnoDB: Highest supported file format is Barracuda.
22:39:40 1190 [Note] InnoDB: 128 rollback segment (s) are active.
22:39:40 1190 [Note] InnoDB: Waiting for purge to start
22:39:40 1190 [Note] InnoDB: 5.6.22 started; log sequence number 44832642
22:39:41 1190 [Note] Server hostname (bind-address): '*'; port: 3306
22:39:41 1190 [Note] IPv6 is available.
22:39:41 1190 [Note]-': 'resolves '::';
22:39:41 1190 [Note] Server socket created on IP :'::'.
22:39:41 1190 [ERROR] Incorrect definition of table mysql. db: expected column 'user' at position 2 to have type char (16), found type char (80 ).
22:39:41 1190 [ERROR] Incorrect definition of table mysql. event: expected column 'definer' at position 3 to have type char (77), found type char (141 ).
22:39:41 1190 [ERROR] Incorrect definition of table mysql. event: expected column 'SQL _ mode' at position 14 to have type set ('Real _ AS_FLOAT', 'Pipes _ as_concat', 'ansi _ QUOTES ', 'ignore _ space', 'not _ used', 'only _ FULL_GROUP_BY ', 'no _ UNSIGNED_SUBTRACTION', 'no _ DIR_IN_CREATE ', 'postgresql', 'Oracle ', 'mssql', 'db2 ', 'maxdb', 'no _ KEY_OPTIONS', 'no _ TABLE_OPTIONS ', 'no _ FIELD_OPTIONS', 'mysql323 ', 'mysql40 ', 'ansi ', 'no _ AUTO_VALUE_ON_ZERO', 'no _ BACKSLASH_ESCAPES ', 'strict _ TRANS_TABLES', 'strict _ ALL_TABLES ', 'no _ ZERO_IN_DATE', 'no _ ZERO_DATE ', 'invalid_dates', 'error _ FOR_DIVISION_BY_ZERO ', 'traditional', 'no _ AUTO_CREATE_USER', 'high _ NOT_PRECEDENCE ', 'no _ ENGINE_SUBSTITUTION ', 'pad _ CHAR_TO_FULL_LENGTH '), found type set ('Real _ AS_FLOAT', 'Pipes _ AS_CONCAT ', 'ansi _ QUOTES', 'Ignore _ space ', 'ignore _ BAD_TABLE_OPTIONS ', 'only _ FULL_GROUP_BY', 'no _ UNSIGNED_SUBTRACTION ', 'no _ DIR_IN_CREATE', 'postgresql ', 'Oracle', 'mssql', 'db2 ', 'maxdb', 'no _ KEY_OPTIONS ', 'no _ TABLE_OPTIONS', 'no _ FIELD_OPTIONS ', 'mysql323', 'mysql40', 'ansi ', 'no _ AUTO_VALUE_ON_ZERO ', 'No _ backslash_escapes', 'strict _ TRANS_TABLES ', 'strict _
22:39:41 1190 [ERROR] Event schedles: An error occurred when initializing system tables. Disabling the Event Scheduler.
22:39:41 1190 [Note]/usr/sbin/mysqld: ready for connections.
Version: '5. 6.22 'socket:'/var/lib/mysql. sock 'port: 3306 MySQL Community Server (GPL)
2015-06-23 23:00:47 7f7038bc0700 InnoDB: Error: Column last_update in table "mysql". "innodb_table_stats" is int unsigned not null but shocould be BINARY (4) not null (type mismatch ).
2015-06-23 23:00:47 7f7038bc0700 InnoDB: Error: Fetch of persistent statistics requested for table "moodle ". "mdl_config" but the required system tables mysql. innodb_table_stats and mysql. innodb_index_stats are not present or have unexpected structure. using transient stats instead.