在启动备用数据库 '%1' (数据库 ID 为 %2)的过程中，RESTORE 语句无法访问它的备用文件('%3')。操作系统错误为 '%4'。诊断该操作系统错误，并更正此问题，然后重试启动操作。

During startup of warm standby database '%1' (database ID %2), its standby file ('%3') was inaccessible to the RESTORE statement. The operating system error was '%4'. Diagnose the operating system error, correct the problem, and retry startup.