The error message you're seeing in both cases is telling you that the file is broken at the points provided (that's what the numbers at the end mean).
SublimeLinter.sublime-settings file is broken near line 62, column 1 and the
Default (OSX).sublime-keymap file is broken at line 1, column 1.
It's hard to say what the actual problem is with any certainty since we can't see the contents. Both files are of type JSON, albeit a slightly more lenient version of JSON. The most common problems is generally forgetting that items need to be separated by commas, but in the case of the
sublime-keymap file being broken at the first character, you may have inadvertently added an extra character to it.