Unable to add packages: ERROR malformed URL ''

I am unable to add packages on a Windows 10 virtual machine with domain authentication. I get the following error for any package I try to add.

> (@v1.6) pkg> add https://github.com/JuliaData/DataFrames.jl
>      Cloning git-repo `https://github.com/JuliaData/DataFrames.jl`
> ERROR: failed to clone from https://github.com/JuliaData/DataFrames.jl, error: GitError(Code:ERROR, Class:Net, malformed URL '')

Same error if I just do

add DataFrames

If a sign on to the virtual machine as an administrator then I can add packages without a problem. Is there a setting I can tweak which will allow me to add packages when signed in as an ordinary user?