Powershell加密错误：为此系统配置的恢复策略包含无效的恢复证书

Question

我正在尝试encrypt files using powershell，使用此命令：

(Get-Item -Path MyFile.txt).Encrypt()

但是我收到了这个错误：

(Get-Item -Path MyFile.txt).Encrypt()

Exception calling "Encrypt" with "0" argument(s): "Recovery policy configured for this system contains invalid recovery certificate.
"
At line:2 char:1
+ (Get-Item -Path MyFile.txt).Encrypt()
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : IOException

导致此错误的原因是什么？为什么我需要恢复证书？