Thanks for contacting support.
Feel free to send us any sample rar file, so we can see what message occurs. https://support.numericalinnovations.com/support/tickets/new
Please remember we just use a 3rd party tool to unrar/unzip, so for any errors we need to pass it onto those developers (we do not develop any unzip code here). In the meantime you should be fine, just using any tool like WinRar and uncompressing the files beforehand. Once uncompressed, then use AutoLoad (menu: File | Import | AutoLoad) or any other FAB 3000 import command.