Following an upgrade of a vCenter to version 6 or later you find that the performance charts, which were working prior to the upgrade, are no longer available in vCommander. There are two known issues which may be impacting you.
External Platforms Services Controller
Changes to vSphere 6 allow for the Platform Services Controller to be installed separately from vCenter. This necessitated a code update for vCommander, which was introduced in vCommander 5.6.0. If you are running an older version of vCommander, please upgrade to current to resolve.
The other reason this occurs is that the SSL certificate installed on the vCommander application server is not valid. vCenter 6 is much more stringent with its handling of requests than its predecessor, and requires the vCommander certificate to be completely valid. The certificate may be invalid because the name used for the certificate does not match the server, or because the certificate has expired. In particular, the self-signed certificate installed by default with legacy versions of vCommander (version 5.5.3 or earlier) is generated so that it is valid for 90 days. vCenter 5 did not care that the certificate had expired, and would fulfill requests regardless. Newer versions of vCommander create 5 year certificates.
You can confirm this is the issue by looking for errors similar to the following in your vCommander log files:
You may additionally receive the error message Unable to obtain SSO token from vCenter in various pages and dialogues while using vCommander.
To resolve, please generate a new self-signed certificate, or install a certificate purchased from a vendor, following the instructions in the KB article Generating and Installing an SSL Certificate.