01:56:03  [mysql]   Error: MySQL shutdown unexpectedly.
01:56:03  [mysql]   This may be due to a blocked port, missing dependencies,
01:56:03  [mysql]   improper privileges, a crash, or a shutdown by another method.
01:56:03  [mysql]   Check the "/xampp/mysql/data/mysql_error.log" file
01:56:03  [mysql]   and the Windows Event Viewer for more clues


How to fix:

quit the XAMPP
cut the All files in C:\xampp\mysql\backup
paste and replace files in C:\xampp\mysql\data
run as administrator the XAMPP

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REPAIR TABLE '.\mysql\db.MYI';

Repair the table:
repair table db;