Claim: “Anything imperceptible cannot really exist.”
Premise 1: Ordinary bodily objects are perceptible through the senses.
Premise 2 (hidden leap): Every existent must be bodily and perceptible.
Conclusion: Non-sensible existence is impossible.
The first premise concerns some bodily entities. The second arbitrarily makes that property necessary for everything while failing to establish that very claim.
The error lies in reducing the universal concept of existence to the narrower sphere of sensory perception without adequate proof.