Failed update HA from terminal and web interface

Hi all,

I am new in this community, I hope I can find issue and provide help using my little knowledge of HA.

I am trying to update ha from 0.70.0 to the last release but I was not successful.

I think something has been moved from the server, it seems that hassio is not able to find the update at the specified link present into the script. Here below my error:

core-ssh:~# hassio -d ha update
DEBUG [CmdHomeassistant]: action->'update', endpoint='update', serverOverride->'', GET->'false', options->'', rawjson->'false', filter->''
DEBUG [ExecCommand]: basepath->'homeassistant', endpoint->'update', serverOverride->'', get->'false', Options->'', Filter->'', RawJSON->'false'
DEBUG [GenerateURI]: basepath->'homeassistant', endpoint->'update', serverOverride->''
DEBUG [RestCall]: data->'xxx://hassio/homeassistant/update', GET->'false', payload->''
DEBUG [RestCall]: ResponseBody->'{"result": "error", "message": null}'
panic: interface conversion: interface is nil, not string

goroutine 1 [running]:
panic(0x2c7050, 0x107ac380)
        /home/travis/.gimme/versions/go1.7.6.linux.amd64/src/runtime/panic.go:500 +0x33c, 0x24, 0x200, 0x0)
        /home/travis/gopath/src/ +0x3c8, 0xd, 0x7e86ee39, 0x6, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/travis/gopath/src/ +0x308
        /home/travis/gopath/src/ +0x540, 0x324b14, 0x10778420, 0x0, 0x0)
        /home/travis/gopath/src/ +0xf0, 0xd, 0x0, 0x0, 0x40bd10, 0x1, 0x1, 0x301e4d, 0x2f, 0x0, ...)
        /home/travis/gopath/src/ +0x6b8*App).Run(0x107668c0, 0x1070a120, 0x4, 0x4, 0x0, 0x0)
        /home/travis/gopath/src/ +0x8b0
        /home/travis/gopath/src/ +0x108

Could you please help me in finding the issue?

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