If you are receiving an error message while trying to import raw files into LR 5, to the effect that "the files could not be read" it is possible that the problem is that you are trying to import the files to a location, HDD, folder, sub-folder for which you do not have "write" permissions.
Make sure that you have full read / write permissions to all drives, folders, and sub folders that you are using with Lightroom.
If Lightroom is being asked to copy, move files to a particular location it requires write permissions to do so. If this cannot be completed then the transaction is aborted, the error message is misleading.
You have not provided much info so this a guess at your problem. Post some more details if you still have problems.