When there is an error or incomplete information in a profile, Sling will not allow additional changes to be saved.
Fortunately, Sling has a way to let you know where the issue is so that you can correct it!
When you notice that the Save button at the bottom of the screen is gray, go ahead and click it anyway. You'll see that it registers your click because it will "roll up" to temporarily display an x before returning to its original appearance.
Now, click on the Profile tab itself to begin scanning for a field that is highlighted (outlined) in red. This will indicate an error.
Common examples of errors are a blank last name field, unsupported characters in the phone field (a period or decimal point is not supported), a 3-digit PIN, or missing details for unavailability. These errors can happen when importing data on occasion.
Once all errors are corrected, you will notice the Save button is blue again, and that you can make additional changes such as updating Unavailability, Wages, and so on.