OK, it seems that the software called “Twitch Developer Rig” was somehow involved. Though I never ended the configuration, refreshing the Manifest seems to solve the problem… I still don’t know exactly how this happened, but i’m pretty sure that will end up realizing.
Thanks!!! Problem solved!!!
(PD: my localhost was set on 127.0.0.1)
PD2: well… after testing many things, the problems wasn’t fixed at all. For some reason, I can’t manage to load the panel.html from my local server… Creating the simple extension I wanted to is getting more completed than I though. and I haven’t even started…