error CS1061: 'IEnumerable<Attribute>' does not contain a definition for 'Length' and no extension method 'Length' accepting a first argument of type 'IEnumerable<Attribute>' could be found (are you missing a using directive or an assembly reference?)

I have this error using Unity 2018 when i try to compile with .Net instead of IL2CPP This is the line where i get the error:

if (methods[i].GetCustomAttributes(typeof(CompilerGeneratedAttribute), true).Length != 0)
            {
                continue;
            }

And, in this other method:

var ret = (Delegate.CreateDelegate(typeof(V), target, method) as V);

also, in this method i used methodinfo instead of Delegate. but then ask about no method using 3 values.
Also added "using system.Linq"
Best regards