How can I fix "serial number unavailable" issue?
Here is my product details:
MacBook Air 13'' Mid 2012
- 2 GHz Intel Core i7
- 8 GB 1600 MHz DDR3
- Intel HD Graphics 4000 1024 MB
Lately, I noticed that my iMessage could not be used. I also noticed that my MacBook Air Serial Number says "Unavailable". It seems to be a problem that happened without my knowledge. I did not replace or change any hardware parts. I did reinstall OS few times since I bought the MacBook.
Any advice would be great.
Thanks!
MacBook Air, OS X Yosemite (10.10.5), null