Issues with castable resins

I get a hole in every single item I print with castable resins.

Everything is fine with white standard formlabs resin. Please see picture attached.

What can be done to avoid this?

.stl file:

I would like to see the stl. I suspect that is the issue

Added how the .stl file looks. Actually there is no difference how supports are placed. Those holes occurs on most of the rings I print. Some smaller, some bigger.

Could you attache the actual cad file and not a picture for review. I also suspect the cad. my email

I suspect something is opening in the stl or you dont have the ring and the support you added unioned into a closed model

if rhino or matrix email me the 3dm file

Here’s the link to stl file for one of my files.

Ok looking at your cad everything looks solid & good. (other then some overlapping of solids) Preform says it needs fixing but I would not let Prefom adjust you cad that may be where your getting the void as well. I never let Preform adjust my cad and have NEVER had a issue.
When you slice your part do you see the void looking at each layer around the void? or is it showing solid?
Is that Formlabs resin?
Check your firmware version and make sure preform matches.