MySQL suddenly stopped working

[funkpunk]

Hi all. I've been using XAMPP for a few months now creating a local site using Joomla and all had been going well until this morning. For no reason, ie no crashes, updates etc, MySQL has stopped working. It tries to load then bombs out with the following error message. Any help would be great as the site was nearly finished!

2016-01-25 11:29:20 d20 InnoDB: Warning: Using innodb_additional_mem_pool_size is DEPRECATED. This option may be removed in future releases, together with the option innodb_use_sys_malloc and with the InnoDB's internal memory allocator.
160125 11:29:20 [Note] InnoDB: Using mutexes to ref count buffer pool pages
160125 11:29:20 [Note] InnoDB: The InnoDB memory heap is disabled
160125 11:29:20 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions
160125 11:29:20 [Note] InnoDB: Memory barrier is not used
160125 11:29:20 [Note] InnoDB: Compressed tables use zlib 1.2.3
160125 11:29:20 [Note] InnoDB: Not using CPU crc32 instructions
160125 11:29:20 [Note] InnoDB: Initializing buffer pool, size = 16.0M
160125 11:29:20 [Note] InnoDB: Completed initialization of buffer pool
160125 11:29:21 [Note] InnoDB: Highest supported file format is Barracuda.
160125 11:29:21 [Note] InnoDB: Log scan progressed past the checkpoint lsn 322677041
160125 11:29:21 [Note] InnoDB: Database was not shutdown normally!
160125 11:29:21 [Note] InnoDB: Starting crash recovery.
160125 11:29:21 [Note] InnoDB: Reading tablespace information from the .ibd files...
160125 11:29:22 [Note] InnoDB: Restoring possible half-written data pages
160125 11:29:22 [Note] InnoDB: from the doublewrite buffer...
InnoDB: Doing recovery: scanned up to log sequence number 322677051
160125 11:29:24 [Note] InnoDB: 128 rollback segment(s) are active.
160125 11:29:24 [Note] InnoDB: Waiting for purge to start
160125 11:29:24 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.6.22-72.0 started; log sequence number 322677051
160125 11:29:24 [Note] Plugin 'FEEDBACK' is disabled.
2016-01-25 11:29:25 1fb0 InnoDB: Assertion failure in thread 8112 in file trx0purge.cc line 703
InnoDB: Failing assertion: purge_sys->iter.trx_no <= purge_sys->rseg->last_trx_no
InnoDB: We intentionally generate a memory trap.
InnoDB: Submit a detailed bug report to http://bugs.mysql.com.
InnoDB: If you get repeated assertion failures or crashes, even
InnoDB: immediately after the mysqld startup, there may be
InnoDB: corruption in the InnoDB tablespace. Please refer to
InnoDB: http://dev.mysql.com/doc/refman/5.6/en/forcing-innodb-recovery.html
InnoDB: about forcing recovery.
160125 11:29:26 [Note] Server socket created on IP: '::'.
160125 11:29:27 [ERROR] Missing system table mysql.roles_mapping; please run mysql_upgrade to create it
160125 11:29:30 [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','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_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','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_A
160125 11:29:30 [ERROR] Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler.
160125 11:29:30 [Warning] Failed to load slave replication state from table mysql.gtid_slave_pos: 1146: Table 'mysql.gtid_slave_pos' doesn't exist
160125 11:29:30 [Note] C:\xampp\mysql\bin\mysqld.exe: ready for connections.
Version: '10.0.17-MariaDB' socket: '' port: 3306 mariadb.org binary distribution