Anyone interop unlocked a Lumia 550? I'm a bit stuck.

I've been trying to interop unlock my Lumia 550, and I've been following the XDA guide but when I get to the part where you have to use iutools to install the acersystemservice I get the error (0X80004005) every time. I'm running CMD as admin and am using the right command so I'm a bit lost.

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