Performing the upgrade of the system via the GUI, referring to the guide System update settings:
 Figure 1. Specify FortiNAC Distribution Directory to be downloaded on FortiNAC GUI. Select firmware version to download:
 Figure 2. Download FortiNAC firmware version.
Downloading firmware in the process page will open in another tab:
 Figure 3. FortiNAC firmware download in process.
Once the download process is completed, the following message will appear:
 Figure 4. FortiNAC firmware download completed.
After the complete download, select the 'Install' button:
 Figure 5. Install FortiNAC firmware.
Select the download version to install:
 Figure 6. Select the FortiNAC firmware version to be installed.
After hitting the Update button, the upgrade process will start.
Important: Do not close the tab browser.
In case of the following error during upgrade, check the downloaded file:
Upgrading 10.1.12.42 with /bsc/campusMgrUpdates/FNAC_KVM-v7.2.7-build0127-FORTINET.out...
Check firmware file ...
Upgrading firmware image from version 7.2.5.101 to 7.2.7.127
Start to restore firmware image..
Cannot read from file /bsc/campusMgrUpdates/FNAC_KVM-v7.2.7-build0127-FORTINET.out
Begin write image to disk...
Errors occured during image upgrade. ret='-1'
Flush firmware failed
This error occurs when the FortiNAC server has a limited bandwidth connection, and it takes too long to download the Firmware from the FortiNAC repository.
Perform the following checks from the CLI to verify if the download file is completed successfully:
- FortiNAC-CLI$gzip --test /bsc/campusMgrUpdates/FNAC_KVM-v7.2.7-build0127-FORTINET.out && echo good
good <----- Command should return good output.
- FortiNAC-CLI$md5sum /bsc/campusMgrUpdates/FNAC_KVM-v7.2.7-build0127-FORTINET.out
636b94047b5257f5308ea6276d196441 FNAC_KVM-v7-build0127-FORTINET.out <----- Command should return the MD5 sum.
Ensure that the FortiNAC server has internet access and can reach the FortiNAC repository fnac-updates.fortinet.net on port HTTP/HTTPS.
If there is a limited bandwidth connection, the download process will take time, and that might cause a compromised downloaded file.
Related articles:
Technical Tip: How to upgrade FortiNAC from GUI
Technical Tip: Upgrade FortiNAC from CLI Technical Tip: Upgrade FortiNAC-F through the CLI
Technical Tip: When trying a GUI upgrade from FortiNAC v7.6.5 GA to v7.6.x GA the FortiNAC does not show the latest version to download | 
