It still works sometimes so I decided not to reopen Issue 4675 but create a new one. Testcases:
---
template t() {
    enum e = 0;
    static if (true)
        enum t = 0;
}

static assert(!__traits(compiles, t!().t == 0)); // Assertion fails
static assert(t!() == 0); // Error: void has no value
---
and
---
template t()
{
    static if (true) {
        enum e = 0;
        enum t1 = 0;
    }
    alias t1 t;
}

static assert(!__traits(compiles, t!().t == 0)); // Assertion fails
static assert(t!() == 0); // Error: void has no value
---