I'm working in, say, K.<x>=QuadraticField(-5,embedding=sqrt(5)*I) and I create a list L of elements of K. I try list_plot(L) and get a pile of errors, recursion depth something something. I try to convert types first, using complex_embedding() or numerical_approx(), but it won't convert, even thought something like x.complex_embedding() works just fine.
Basically type converting in number fields is the bane of my existence and makes Sage absolutely worthless to me.