I've had quite a few occasions recently where when I put a file I sliced through Photon File Validator I find massive islands. Looking into it, it seems like randomly Chitubox slicer is just missing an element of the file for an entire layer, creating a gap that can break the print.
Looking at it in the slice view I can see Chitubox shows the gap for the layer the issue, so it's not just the file validator. Slicing the same models in other slicers (Like Lychee) doesn't have the issue. I'm currently often doing my support setup in chitu, exporting to STL then slicing in another program... but this is really annoying.
Screenshot: Chitu slicer missing an element.
Next layer it works out that supports should be solid, but the damage is already done. I've seen this with both supports that are part of the STL, thin areas of models, and even supports added by Chitubox itself. It seems like there's just some circumstance where for 1 layer of the slicing it drops a certain shape.
Screenshot - same thing a few layers up. You can see the model is solid:
I saw this once a few versions ago, but I can't remember the exact version number & a patch came out at the time which seemed to solve it...
I've been experiencing this same issue quite frequently. I can't be certain, but it seems to occur more common when there are multiple objects loaded in a project. Once it occurs a single time in a file it will seemingly reoccur every time I try to slice the file, though not always in the same layer or location.