help with files for AI

Every file I import is having an issue. There are lines through the design. it doesn't matter if it is a .eps or .ai - and when i trace a file, it happens too.  I have been using AI for YEARS and this has never happened. I have creative cloud. i uninstalled, then re-installed. and still the same. I don't know how to fix this HELP! It started happening after updating the app through CC...