Simpletech 500 external hard drive. when i access the external hard drive the content loads as it

Question

when i access the external hard drive the content loads as it always does but now i recieve an error message: requested file not found, the link you followed may be outdated or inaccurate it then provides the file name this drive worked great for a while. i have had it for 1 month. i ran a virus scan and no threats reported. my computer says device is working properly. help!