To update the firmware on your SSD, follow the steps below. Please ensure you are using an internal SuperDrive for the update, and that your SSD is internally connected to a SATA port.
1. Download the latest firmware here : http://www.crucial.com/usa/en/support-ssd-firmware
2. Click on the .iso to highlight it. Hold down Control and click on the .iso a second time.
3. Select “Open With” in the menu that comes up, then select Disk Utility.
4. In the list of drives in Disk Utility, select the ISO
5. Insert a blank CD into the SuperDrive
6. Click “Burn”
7. Ensure “Verify burned data” is checked
8. Once the burn is complete, shut down your Mac
9. Press and hold the Option key, and power Mac back on.
10. On the Startup Manager screen, wait for the firmware CD to appear. This may take a minute, or longer.
11. Click on the CD named “Windows” to highlight it, and then click the arrow just below the CD symbol to boot from the firmware CD.
12. Let the update utility run, following the steps on the screen to update your SSD firmware.
Once the firmware update has finished, use the power button to shut down and restart your Mac, and let it boot back up to your desktop.
Below is a video illustrating the process. The video uses an M500, but the process is the same for all Crucial 2.5" SSDs.