Here in the following video you can see actual and 100% easy Solution for " ioc1.ic7 (260 bytes) - INCORRECT LENGTH: 279 bytes " error ,
watch the video for easy solution for ioc1.ic7 error
if someone is facing ioc1.ic1 (260 bytes) - INCORRECT LENGTH: 279 bytes , this error usually comes in MAME Game cadillacs and dinosaurs so for Solution watch following video ,