Warning: main() [function.include]: Failed opening

Discuz论坛安装报错：

 

如何解决这个问题Warning: main() [function.include]: Failed opening

升级SS以后,在输入验证码的步骤出现如下提示,请问什么原因如何解决

Warning: main(/data/home/zn2041/htdocs/./data/system/crons.cache.php): failed to open stream: No such file or directory in /data/home/zn2041/htdocs/function/cron.func.php on line 16

Warning: main(): Failed opening '/data/home/zn2041/htdocs/./data/system/crons.cache.php' for inclusion (include_path='.:/usr/local/lib/php') in /data/home/zn2041/htdocs/function/cron.func.php on line 16

 

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 问题原因，这个网站文件根目录的上一级目录没有读取+写入权限。