XAMPP MySQL won't start after rebooting

Question

This happened without any forewarning, the last thing I registered in the database was a column with the autoincrement property.

This is the error log:

2022-01-27 17:38:28 0 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions
2022-01-27 17:38:28 0 [Note] InnoDB: Uses event mutexes
2022-01-27 17:38:28 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2022-01-27 17:38:28 0 [Note] InnoDB: Number of pools: 1
2022-01-27 17:38:28 0 [Note] InnoDB: Using SSE2 crc32 instructions
2022-01-27 17:38:28 0 [Note] InnoDB: Initializing buffer pool, total size = 16M, instances = 1, chunk size = 16M
2022-01-27 17:38:28 0 [Note] InnoDB: Completed initialization of buffer pool
2022-01-27 17:38:28 0 [Note] InnoDB: 128 out of 128 rollback segments are active.
2022-01-27 17:38:28 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2022-01-27 17:38:28 0 [Note] InnoDB: Setting file '\xampp\mysql\data\ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2022-01-27 17:38:28 0 [Note] InnoDB: File '\xampp\mysql\data\ibtmp1' size is now 12 MB.
2022-01-27 17:38:28 0 [Note] InnoDB: Waiting for purge to start
2022-01-27 17:38:28 0 [Note] InnoDB: 10.4.22 started; log sequence number 809938; transaction id 1388
2022-01-27 17:38:28 0 [Note] InnoDB: Loading buffer pool(s) from C:\xampp\mysql\data\ib_buffer_pool
2022-01-27 17:38:28 0 [Note] Plugin 'FEEDBACK' is disabled.
2022-01-27 17:38:28 0 [Note] Server socket created on IP: '::'.

I get this error in XAMPP:

5:42:49 PM  [mysql]     Error: MySQL shutdown unexpectedly.
5:42:49 PM  [mysql]     This may be due to a blocked port, missing dependencies, 
5:42:49 PM  [mysql]     improper privileges, a crash, or a shutdown by another method.
5:42:49 PM  [mysql]     Press the Logs button to view error logs and check
5:42:49 PM  [mysql]     the Windows Event Viewer for more clues
5:42:49 PM  [mysql]     If you need more help, copy and post this
5:42:49 PM  [mysql]     entire log window on the forums

The database would open for days after without me doing any other modifications to it, then suddenly this error happened today.

Answer 1

I fixed it by copying the multi-master.info from the backup folder, although I'd still like to know why this happened in the first place if anyone has any ideas.

The multi.master.info is empty.

Answer 2

Rename the folder mysql/data to mysql/data_old (you can use any name)

Create a new folder mysql/data

Copy the content that resides in mysql/backup to the new mysql/data folder

Copy all your database folders that are in mysql/data_old to mysql/data

Finally copy the ibdata1 file from mysql/data_old and replace it inside mysql/data folder

Start MySQL from XAMPP control panel