Okay- So your printer is fine.
I imported the file and it had clearly corrupted geometry.
Most of the issues disappeared because of the software I imported it into…
But here are screen shots showing two overt errors.
In the upper picture you can see two little ‘shards’ that are floating in space separate from the model proper.
You won’t SEE these in your model- because they are the result of my software trying to make solids of the geometry in your file… what they imply is that there are spurious segments, or vertices unconnected to any other vertice that are bridging across the opening in your model.
The printer is seeing this as a “FILL” its trying to print.
The lower picture shows one of your numerals squashed and slanted over- this is the result of the top surface of the numeral being in the file, but not properly connected to the bottom of the numeral… your software tried to do a slice and stitch of the numeral but the sidewalls of the numeral did not export in the resulting file.
I corrected the numeral by copying and pasting one of the other numeral '1’s that imported correctly.
Here is a link to a version of the model that should print correctly.
However- in looking at the model I note that none of your numerals are correctly drafted for an injection tool. The edges of the numerals on the Lower sides ( facing the hole) are all Undercuts that will prevent the release of a rigid casting.
If you attempt to use the large triangular hole as an ejector pin, the result will be the fracturing of the edges of the numerals- or an inability to get the casting out of the cavity at all.
The printed resin tool is more likely to fracture than the urethanes you might fill it with, but you may well see damage to both tool and casting.
You might get away with casting Vinyl dies in this mold- but nothing rigid.
For something like this, the numerals should be modeled as very shallow rounded grooves such that no portion of an engraved numeral is less than 1 full degree of draft relative to the motion of the ejector pin.