I have installed the latest android studio and I try to sync an old project that I download from GitHub and I get this Error:
cvc-complex-type.2.4.a: Invalid content was found starting with element 'base-extension'. One of '{codename, tag}' is expected.
and This
CVC-complex-type.2.4.d: Invalid content was found starting with element 'base-extension'. No child element is expected at this point.