Guide buffer is empty
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## Describe the behavior that you expect from SpaceVim

When hitting any of the leaders the guide buffer should open with a list of valid options.

[MappingsGuide](https://spacevim.org/documentation/#mappings-guide)

## Describe the problem

The guide buffer opens, but it is empty. Same behavior with any of the leaders.

## Describe steps to reproduce the problem

This is a new SpaceVim install and it hasn't ever worked properly. 

SpaceVim is installed in WSL (Debian) and I'm opening WSL via MobaXterm and Tmux.

The same behavior happens in the default WSL debian command line window.

## Provide debug information from SpaceVim

I get an error when using 'SPC-h-I', but here is the output of SPDebugInfo.

[SpaceVim-debug.txt](https://github.com/SpaceVim/SpaceVim/files/5547260/SpaceVim-debug.txt)

## If needed, provide Screenshots and/or Video captures

Empty guide buffer:
![spacevim-empty-guide-buffer](https://user-images.githubusercontent.com/17345083/99272589-94ac8a00-27ed-11eb-81a1-57a9c5cbfef7.PNG)

Debug error:
![spacevim-debug-error](https://user-images.githubusercontent.com/17345083/99272606-98d8a780-27ed-11eb-89aa-90448737a3d1.PNG)


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