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Computing ranks of elliptic curves over number fields is not easy, but should not give the error message posted above. Can you try a smaller example, such as

sage: E1 = EllipticCurve(K1,[0,0,0,0,2])
sage: E1.rank()
2


Secondly, if E is an elliptic curve over Q then its rank over K=Q(sqrt(d)) is E.rank()+E.quadratic_twist(d).rank(), for example here

sage: E = EllipticCurve([0,0,0,0,2])
sage: E.rank() + E.quadratic_twist(-3).rank()
2


or for your examples

sage: E = EllipticCurve([0,0,0,0,2332])
sage: E.rank() + E.quadratic_twist(-3).rank()
2
sage: E = EllipticCurve([0,0,0,-15,22])
sage: E.rank() + E.quadratic_twist(-3).rank()
0