Writing to Global Memory Causing Crash in OpenCL in For Loop - opencl

Question

One of my OpenCL helper functions writing to global memory in one place runs just fine, and the kernel executes typically. Still, when run from directly after that line, it freezes/crashes the kernel, and my program can't function.
The values in this function change (different values for an NDRange of 2^16), and therefore the loops change as well, and not all threads can execute the same code because of the conditionals.
Why exactly is this an issue? Am I missing some kind of memory blocking or something?
void add_world_seeds(yada yada yada...., const uint global_id, __global long* world_seeds)
for (; indexer < (1 << 16); indexer += increment) {
long k = (indexer << 16) + c;
long target2 = (k ^ e) >> 16;
long second_addend = get_partial_addend(k, x, z) & MASK_16;
if (ctz(target2 - second_addend) < mult_trailing_zeroes) { continue; }
long a = (((first_mult_inv * (target2 - second_addend)) >> mult_trailing_zeroes) ^ (J1_MUL >> 32)) & mask;
for (; a < (1 << 16); a += increment) {
world_seeds[global_id] = (a << 32) + k; //WORKS HERE
if (get_population_seed((a << 32) + k, x, z) != population_seed_state) { continue; }
world_seeds[global_id] = (a << 32) + k; //DOES NOT WORK HERE
}
}
for (; a < (1 << 16); a += increment) {
world_seeds[global_id] = (a << 32) + k; //WORKS HERE
if (get_population_seed((a << 32) + k, x, z) != population_seed_state) { continue; }
world_seeds[global_id] = (a << 32) + k; //DOES NOT WORK HERE
}

Answer 1

There was in fact a bug causing the undefined behavior in the code, in particular the main reversal kernel included a variable in the arguments called "increment", and in that same kernel I defined another variable called increment. It compiled fine but led to completely all over the wall wrong results and memory crashes.