Assertion Error - Installation error

[EconometricsBySimulation]

Trying to install RCall and getting the following error. Thanks for your efforts.
Pkg.add("RCall")

add RCall
Updating registry at ...\.juliapro\JuliaPro_v1.1.1.1\registries\JuliaPro
Updating git-repo https://pkg.juliacomputing.com//registry/JuliaPro
ERROR: AssertionError: name == "helper"
Stacktrace:
[1] credential_helpers(::LibGit2.GitConfig, ::LibGit2.GitCredential) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\LibGit2\src\gitcredential.jl:219
[2] approve(::LibGit2.GitConfig, ::LibGit2.UserPasswordCredential, ::String) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\LibGit2\src\gitcredential.jl:289
[3] #approve#33(::Bool, ::Function, ::LibGit2.CredentialPayload) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\LibGit2\src\types.jl:1404
[4] approve at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\LibGit2\src\types.jl:1394 [inlined]
[5] #fetch#115(::String, ::String, ::Array{String,1}, ::LibGit2.UserPasswordCredential, ::Dict{Symbol,Tuple{Ptr{Nothing},Any}}, ::Function, ::LibGit2.GitRepo) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\LibGit2\src\LibGit2.jl:301
[6] (::getfield(LibGit2, Symbol("#kw##fetch")))(::NamedTuple{(:remoteurl, :callbacks, :credentials, :refspecs),Tuple{String,Dict{Symbol,Tuple{Ptr{Nothing},Any}},LibGit2.UserPasswordCredential,Array{String,1}}}, ::typeof(LibGit2.fetch), ::LibGit2.GitRepo) at .\none:0
[7] #fetch#4(::Nothing, ::Nothing, ::Base.Iterators.Pairs{Symbol,Array{String,1},Tuple{Symbol},NamedTuple{(:refspecs,),Tuple{Array{String,1}}}}, ::Function, ::LibGit2.GitRepo, ::Nothing) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\GitTools.jl:147
[8] #fetch at .\none:0 [inlined] (repeats 2 times)
[9] update_registries(::Pkg.Types.Context, ::Array{Pkg.Types.RegistrySpec,1}) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\Types.jl:1247
[10] update_registries at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\Types.jl:1219 [inlined]
[11] #handle_repos_add!#61(::Bool, ::Nothing, ::Function, ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\Types.jl:719
[12] #handle_repos_add! at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\API.jl:0 [inlined]
[13] #add_or_develop#17(::Symbol, ::Bool, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\API.jl:47
[14] (::getfield(Pkg.API, Symbol("#kw##add_or_develop")))(::NamedTuple{(:mode,),Tuple{Symbol}}, ::typeof(Pkg.API.add_or_develop), ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at .\none:0
[15] do_add!(::Dict{Symbol,Any}, ::Array{Pkg.Types.PackageSpec,1}, ::Dict{Symbol,Any}) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\REPLMode.jl:672
[16] #invokelatest#1(::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Any, ::Any, ::Vararg{Any,N} where N) at .\essentials.jl:742
[17] invokelatest(::Any, ::Any, ::Vararg{Any,N} where N) at .\essentials.jl:741
[18] do_cmd!(::Pkg.REPLMode.PkgCommand, ::REPL.LineEditREPL) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\REPLMode.jl:563
[19] #do_cmd#31(::Bool, ::Function, ::REPL.LineEditREPL, ::String) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\REPLMode.jl:538
[20] do_cmd at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\REPLMode.jl:534 [inlined]
[21] (::getfield(Pkg.REPLMode, Symbol("##53#56")){REPL.LineEditREPL,REPL.LineEdit.Prompt})(::REPL.LineEdit.MIState, ::Base.GenericIOBuffer{Array{UInt8,1}}, ::Bool) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\Pkg\src\REPLMode.jl:988
[22] #invokelatest#1 at .\essentials.jl:742 [inlined]
[23] invokelatest at .\essentials.jl:741 [inlined]
[24] run_interface(::REPL.Terminals.TextTerminal, ::REPL.LineEdit.ModalInterface, ::REPL.LineEdit.MIState) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\REPL\src\LineEdit.jl:2273
[25] run_frontend(::REPL.LineEditREPL, ::REPL.REPLBackendRef) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\REPL\src\REPL.jl:1035
[26] run_repl(::REPL.AbstractREPL, ::Any) at C:\Users\julia\AppData\Local\Julia-1.1.1\share\julia\stdlib\v1.1\REPL\src\REPL.jl:192
[27] (::getfield(Base, Symbol("##734#736")){Bool,Bool,Bool,Bool})(::Module) at .\client.jl:362
[28] #invokelatest#1 at .\essentials.jl:742 [inlined]
[29] invokelatest at .\essentials.jl:741 [inlined]
[30] run_main_repl(::Bool, ::Bool, ::Bool, ::Bool, ::Bool) at .\client.jl:346
[31] exec_options(::Base.JLOptions) at .\client.jl:284
[32] _start() at .\client.jl:436