FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
Article Id 274274
Description This article describes that Donut charts are not showing from the Asset widget.
Scope VM or physical device and FortiGate v7.4.0+

From the previous version (7.2.5 and lowest), there is a Device Inventory Widget which shows like image below:




This widget changes on v7.4.0+ to Combine the Device Inventory widget and Asset Identity Center:




But if the charts are not showing, it means that the device have no internal disk, then it is no longer supported

If this is really necessary to have, it is necessary to acquire a device with an internal disk, install a new disk for FortiatGe-VM or install a FortiOS matured version.


Related document:

Combine the Device Inventory widget and Asset Identity Center page

Technical Tip: Recommended Release for FortiOS