Anaconda添加vpython库报错怎么解决

在Anaconda prompt里安装vpython库时总是发生下面的报错，想问问大家该怎么解决

Preparing transaction: done
Verifying transaction: done
Executing transaction: failed
ERROR conda.core.link:_execute(502): An error occurred while installing package 'defaults::charset-normalizer-2.0.4-pyhd3eb1b0_0'.
CondaError: Cannot link a source that does not exist. D:\Anaconda\Scripts\conda.exe
Running `conda clean --packages` may resolve your problem.
Attempting to roll back.

Rolling back transaction: done

CondaError: Cannot link a source that does not exist. D:\Anaconda\Scripts\conda.exe
Running `conda clean --packages` may resolve your problem.

加个清华源 pip install vpython -i https://pypi.tuna.tsinghua.edu.cn/simple