更新散景时出现问题:[WinError 126] 找不到指定的模块

I tried to update bokeh to 1.4.0 with the command conda update bokeh but encountered the problem of [WinError 126] The specified module could not be found as shown below

(base) D:Usersjng>conda update bokeh
Collecting package metadata (repodata.json): done
Solving environment: 
Warning: >10 possible package resolutions (only showing differing packages):
  - anaconda/noarch::keras-applications-1.0.8-py_0, anaconda/noarch::keras-preprocessing-1.1.0-py_1, defaults/win-64::h5py-2.8.0-py36hf7173ca_2, defaults/win-64::keras-base-2.2.4-py36_0
  - anaconda/noarch::keras-preprocessing-1.1.0-py_1, defaults/noarch::keras-applications-1.0.8-py_0, defaults/win-64::h5py-2.8.0-py36hf7173ca_2, defaults/win-64::keras-base-2.2.4-py36_0
  - anaconda/noarch::keras-applications-1.0.8-py_0, defaults/noarch::keras-preprocessing-1.1.0-py_1, defaults/win-64::h5py-2.8.0-py36hf7173ca_2, defaults/win-64::keras-base-2.2.4-py36_0
  - defaults/noarch::keras-applications-1.0.8-py_0, defaults/noarch::keras-preprocessing-1.1.0-py_1, defaults/win-64::h5py-2.8.0-py36hf7173ca_2, defaults/win-64::keras-base-2.2.4-py36_0
  - anaconda/noarch::keras-applications-1.0.8-py_0, anaconda/win-64::keras-base-2.2.4-py36_0, defaults/noarch::keras-preprocessing-1.1.0-py_1, defaults/win-64::h5py-2.8.0-py36hf7173ca_2
  - anaconda/win-64::keras-base-2.2.4-py36_0, defaults/noarch::keras-applications-1.0.8-py_0, defaults/noarch::keras-preprocessing-1.1.0-py_1, defaults/win-64::h5py-2.8.0-py36hf7173ca_2
  - anaconda/noarch::keras-applications-1.0.8-py_0, anaconda/noarch::keras-preprocessing-1.1.0-py_1, anaconda/win-64::keras-base-2.2.4-py36_0, defaults/win-64::h5py-2.8.0-py36hf7173ca_2
  - anaconda/noarch::keras-preprocessing-1.1.0-py_1, anaconda/win-64::keras-base-2.2.4-py36_0, defaults/noarch::keras-applications-1.0.8-py_0, defaults/win-64::h5py-2.8.0-py36hf7173ca_2
  - anaconda/noarch::keras-applications-1.0.8-py_0, anaconda/noarch::keras-preprocessing-1.1.0-py_1, anaconda/win-64::h5py-2.8.0-py36hf7173ca_2, anaconda/win-64::keras-base-2.2.4-py36_0
  - anaconda/noarch::keras-applications-1.0.8-py_0, anaconda/win-64::h5py-2.8.0-py36hf7173ca_2, anaconda/win-64::keras-base-2.2.4-py36_0, defaults/noarch::keras-preprocessing-1.1.0-py_1
  ... and othedone

## Package Plan ##

  environment location: D:UsersjngAppDataLocalContinuumanaconda3

  added / updated specs:
    - bokeh


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    h5py-2.8.0                 |   py36hf7173ca_2         822 KB
    keras-base-2.2.4           |           py36_0         458 KB
    ------------------------------------------------------------
                                           Total:         1.3 MB

The following packages will be SUPERSEDED by a higher-priority channel:

  h5py                                             anaconda --> pkgs/main
  keras-base                                       anaconda --> pkgs/main


Proceed ([y]/n)? y


Downloading and Extracting Packages
keras-base-2.2.4     | 458 KB    |                  |   0%
h5py-2.8.0           | 822 KB    |                  |   0%

[WinError 126] The specified module could not be found
[WinError 126] The specified module could not be found

这太令人困惑了，因为我想更新 bokeh 但是为什么 conda 想下载不相关的包 keras-base-2.2.4 和 h5py.-2.8.0 (已经安装在我的 conda 库中)?另外，消息 [WinError 126] The specified module could not be found 是什么意思?有人可以帮我解决这个问题吗?谢谢