R错误：无法找到'multcomp'所需的包'mvtnorm'

Question

我需要安装包multcomp。安装包（install.packages("multcomp")）后，我收到消息：

package ‘zoo’ successfully unpacked and MD5 sums checked
package ‘mvtnorm’ successfully unpacked and MD5 sums checked
package ‘TH.data’ successfully unpacked and MD5 sums checked
package ‘sandwich’ successfully unpacked and MD5 sums checked
package ‘multcomp’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
    C:\Users\kbn982\AppData\Local\Temp\RtmpwbLdqW\downloaded_packages 

但是当我加载库时会出现一条错误消息：

  

错误：无法找到'multcomp'所需的包'mvtnorm'。

我还尝试将库位置更改为另一个路径。 但我不知道为什么我会收到这条消息。