安裝完XAMPP后啟動mysql，發現啟動失敗也沒有任何提示，通過查看mysql_error日志，描述：
2021-08-11 18:56:53 0 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions 2021-08-11 18:56:53 0 [Note] InnoDB: Uses event mutexes 2021-08-11 18:56:53 0 [Note] InnoDB: Compressed tables use zlib 1.2.11 2021-08-11 18:56:53 0 [Note] InnoDB: Number of pools: 1 2021-08-11 18:56:53 0 [Note] InnoDB: Using SSE2 crc32 instructions 2021-08-11 18:56:53 0 [Note] InnoDB: Initializing buffer pool, total size = 16M, instances = 1, chunk size = 16M 2021-08-11 18:56:53 0 [Note] InnoDB: Completed initialization of buffer pool 2021-08-11 18:56:53 0 [Note] InnoDB: 128 out of 128 rollback segments are active. 2021-08-11 18:56:53 0 [Note] InnoDB: Creating shared tablespace for temporary tables 2021-08-11 18:56:53 0 [Note] InnoDB: Setting file 'E:\xampp\mysql\data\ibtmp1' size to 12 MB. Physically writing the file full; Please wait ... 2021-08-11 18:56:53 0 [Note] InnoDB: File 'E:\xampp\mysql\data\ibtmp1' size is now 12 MB. 2021-08-11 18:56:53 0 [Note] InnoDB: Waiting for purge to start 2021-08-11 18:56:53 0 [Note] InnoDB: 10.4.20 started; log sequence number 300369; transaction id 170 2021-08-11 18:56:53 0 [Note] InnoDB: Loading buffer pool(s) from E:\xampp\mysql\data\ib_buffer_pool 2021-08-11 18:56:53 0 [Note] Plugin 'FEEDBACK' is disabled. 2021-08-11 18:56:53 0 [Note] Server socket created on IP: '::'.
解決方法：
將 /xampp/mysql/backup/中所有文件復制並覆蓋 /xampp/mysql/data/中的所有文件，重啟xampp,再啟動mysql,成功!