I have a Seagate Expansion Drive 1.5 TB. When I plug it into my Mac laptop it only sometimes pops up. When it does pop up, the drive can be opened and I can see the folders. When I click on a folder it doesn’t show the files, it just keeps loading. Shortly after my Mac says the expansion drive was improperly ejected. I would like to fix the drive, I have files on it that I still want. Please help! Thanks.