Hi I had a urine test and had positive leukocyte esterase. No other symptoms. Can it mean anything other than a UTI or could it be lab error?

Bacteria. It means you have bacteria in your urine sample. It could mean a UTI, but it also could just be a contaminant, like cells from your skin. If it was a very small amount, and the rest of your urine test was normal, than probably nothing.