typeerror: cannot read property 'colors' of undefined

[calulelalu]

I installed grafana with grafana-radar-panel on two machines, one behind a proxy and one not.
The panel has a Mysql datasource and I have a sql query that retrieves the value for the panel.
I configured all the proxy settings and grafana starts gracefully on both machines and installs the plugins but on the behind-proxy-machine I get an error on all my radar panels. When I click on Edit to inspect the panel settings the page breaks up and I receive a blank page with the error:
typeerror: cannot read property 'colors' of undefined

It seems that $rootScope is undefined at some point.

I have the same exactly installation on both the machines but only on the behind-proxy-machine I have this issue.

Other plugins panels are working, for example I am using grafana-piechart-panel without any issue.
Can you take a look at the issue?