Random Unintended Layer/Hole filled randomly

[chrisbellcreations 0]

Hello. I'm fairly new to 3D printing but have built a lot of simple models. Just started using Cura and am having trouble with this one little layer that appears toward the bottom of the model and only in one piece. The piece on the right in the pictures is supposed to have a clean hole straight through it from top to bottom. I've gone through most of the settings I can think of that could be related to this issue and the only thing that made a difference was unchecking the Union Overlapping Volumes setting. It cleared up the layer toward the bottom but added another one up top. It's probably a messy model but honestly, its such a simple flanged pipe looking thing that I'm not sure where to begin cleaning it up. I'm really scratching my head on this one. Any help is super appreciated!

AI3M_GearHolder7.3.gcode

[NBull 12]

Hi. To me it looks like a model that's not watertight. or have some other mesh error.

Most the time Cura can overcome small imperfections in the mesh, but sometimes Cura misreads them and slice it wrong.

 

If you upload the stl or step file I can have a look at it.

Edited September 11 by NBull