@ When the documentation says "default administrator account" it does not say "domain" or local builtin on the server. Which does it mean?
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Any user who is in Group "Administrators" be it local or domain should be fine.
@ Why? is there a known issue or is it just that it has not been tested?
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I don't know all reasons but some things don't work unless you login as the Administrator user i.e. a user with Administrative privileges. What I have noticed and remember is that some WFA applications access the windows registry and a non-administrator user doesn't have the right for it.
WFA service by default runs using the Local account, and if the local account doesn't have all permissions , WFA functioning could be affected.
But I haven't tested much on this area.
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