CONDA create, CONDA install, CONDA update error conda.core.subdir_ data.Response304ContentUnchanged

One 、 The cause of the problem

My original environment is tensorflow1.5, Later upgrade to tensorflow2.1, But I found that some of the original code can't be written in tensorflow 2.0 The above operation , If you want to change the code, it does involve some underlying API, It's not easy for me , So I want to create another environment tensorflow1.5, Let these old codes be 1.5 Version of tensorflow Run under . So I went into anaconda prompt Command line to operate ：conda create -n tensorflow1.5, So the following error is reported ：

Traceback (most recent call last):
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\subdir_data.py", line 227, in _load
        mod_etag_headers.get('_mod'))
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\subdir_data.py", line 574, in fetch_repodata_remote_request
        raise Response304ContentUnchanged()
    conda.core.subdir_data.Response304ContentUnchanged

    During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
      File "C:\DEV\Anaconda3\lib\site-packages\conda\exceptions.py", line 819, in __call__
        return func(*args, **kwargs)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\cli\main.py", line 78, in _main
        exit_code = do_call(args, p)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\cli\conda_argparse.py", line 77, in do_call
        exit_code = getattr(module, func_name)(args, parser)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\cli\main_create.py", line 11, in execute
        install(args, parser, 'create')
      File "C:\DEV\Anaconda3\lib\site-packages\conda\cli\install.py", line 235, in install
        force_reinstall=context.force,
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\solve.py", line 518, in solve_for_transaction
        force_remove, force_reinstall)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\solve.py", line 451, in solve_for_diff
        final_precs = self.solve_final_state(deps_modifier, prune, ignore_pinned, force_remove)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\solve.py", line 180, in solve_final_state
        index, r = self._prepare(prepared_specs)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\solve.py", line 592, in _prepare
        self.subdirs, prepared_specs)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\index.py", line 215, in get_reduced_index
        new_records = query_all(spec)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\index.py", line 184, in query_all
        return tuple(concat(future.result() for future in as_completed(futures)))
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\subdir_data.py", line 95, in query
        self.load()
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\subdir_data.py", line 149, in load
        _internal_state = self._load()
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\subdir_data.py", line 233, in _load
        mod_etag_headers.get('_mod'))
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\subdir_data.py", line 280, in _read_local_repdata
        _internal_state = self._process_raw_repodata_str(raw_repodata_str)
      File "C:\DEV\Anaconda3\lib\site-packages\conda\core\subdir_data.py", line 317, in _process_raw_repodata_str
        json_obj = json.loads(raw_repodata_str or '{}')
      File "C:\DEV\Anaconda3\lib\json\__init__.py", line 348, in loads
        return _default_decoder.decode(s)
      File "C:\DEV\Anaconda3\lib\json\decoder.py", line 337, in decode
        obj, end = self.raw_decode(s, idx=_w(s, 0).end())
      File "C:\DEV\Anaconda3\lib\json\decoder.py", line 353, in raw_decode
        obj, end = self.scan_once(s, idx)
    json.decoder.JSONDecodeError: Expecting property name enclosed in double quotes: line 169024 column 26 (char 4767569)
So I began to search on the Internet （ Roast Baidu , No suitable results can be found , Still google A lot of the same questions have been searched on ）, I find that many people encounter similar or the same problems , But there is no good solution , Until I read https://github.com/conda/conda/issues/8051, thank EricThomson.

Two 、 resolvent

1. To look at first channels

conda config --get channels

The result of running on my computer is ：

--add channels 'defaults'   # lowest priority
--add channels 'https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge'
--add channels 'https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/msys2'
--add channels 'https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/pytorch/'
--add channels 'https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/r'
--add channels 'https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free'
--add channels 'https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main'   # highest priority

2. remove conda-forge

conda config --remove channels https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge

Problem solved , I began to happily create a new environment .

3、 ... and 、 Digression

I wonder why I used it last month conda Successfully created the environment , After a month, you can't create an environment ？ I thought about it , Maybe I'm upgrading the installation tensorflow2.1 The image source of Tsinghua is used , So my channels It defaults to the image of Tsinghua , And just on the mirror conda-forge Cause my mistake . These are guesses , Not verified , If you have any friends who know, please don't hesitate to give advice .