Printing Troubles Not printing Cavities

Hello,
I was trying to print couple of designs and having issues with that. The cavities are 20 mm long and have diameter of 5mm in the design, but when I am trying to print it, these cavities are always filled with weird looking solid cured mass always different and irregular in shape. Also the prints sometimes are not sticking to the plate aswell. What should I do, Should I try changing VAT or try changing film of VAT (Can I do that ?) ?
Thanks & Regards

have you checked the model for errors by running it through netfabb? can you provide some more information and photos so we can see?

can you show us the model oriented in Asura?
did you have vent holes, hollow created ?