Consider the following code:
DSolveValue[{y''[x] - x y'[x] + (y[x])^2 == x, y[1] == 1, y'[x] == 0}, y[x], x]
DSolveValue::overdet: There are fewer dependent variables than equations, so the system is overdetermined What I should do?
You may have meant y'[1] == 0 instead of y'[x] == 0.
y'[1] == 0
y'[x] == 0