I have an old Mac using Lightroom 4. My new Mac has Lightroom 6 installed. I want to transfer the entire photo collection and catalog over to the new computer into Lightroom 6. I did make an attempt already using an external hard drive but the Photo Collection photos all appeared as gray boxes (no visible pictures). So, what is the proper way to transfer the photos over so that Lightroom 6 looks the way it was on LIghtroom 4?
Any help is appreciated.