For the past 2 years of working on my map, I have never been able to solve this one constant error. For some reason a get an error that states: "AI (Entity #, origin # # #, couldn't find path to goal)". What makes this so weird is the fact that it doesn't seem to affect game play as they find all of the players just fine, with no exception. I have no idea what could possibly be causing this, I have spent 200+ hours trying to solve this stupid bug. I would prefer to have no errors in my final map. I have tried having the zombies spawn on a path node, I have used ai_shownodes 1 (with no problems/red x's and with red arrows coming from each window), I have moved the spawners up and down with no luck. This error comes from each one of my spawners. Even though it doesn't appear to make a difference, something must be causing it. The other weird part it is only happens 60-80% off the time, as in not every zombie spawned has this error. I have my zones set up properly and do most of my testing in the first room (to eliminate variation). The spawners are inside of the zone's volume (if that means anything). I would be very grateful if someone has any ideas.

I have attached a few images below of different spawners in the first room

I think its just a debug message when it switches between paths until zombs are through the boards/windows.
I've seen it in my logs before and i never have pathing problems.
You can check with "ai_shownodes 1" and "ai_showpaths 1" to be sure they are pathing to the boards/windows, then immediately to the players after the windows are down.

Was it consistent. I always get these errors without fail. It makes debugging a pain because my console is constantly getting spammed.

It shouldnt fill your console.
The error comes from zombiemode_spawner::zombie_assure_nodes() and if you run in devmode it says something like "zombie didn't move for 1 second" at the same time it prints the error you posted.
From zombie_assure_nodes() there is 2 loops.
The first loop goes through the exterior_goals/entrance_nodes then the second loop (from dlc3.assurenodes = true in mapname.gsc) goes through the goals again but returns even more.
If it doesnt find a window/goal it damages the zombie.
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You can get rid of the both errors if you put more pathnodes behind the windows. 3 to 20 nodes worked.
I tested this in a fresh sniperbolt tutorial room and it got rid of the errors.