Unknown provider js error, Query editor is empty in Edit Panel

Hello, I’m running Grafana v7.1.3 (5723d951af) with ‘Performance Co-Pilot’ plugin. It worked fine for a few days, but now I can’t edit any queries - when I open ‘Edit Panel’, Query editor is empty. Javascript console shows
Error: [$injector:unpr] Unknown provider: variableSrvProvider <- variableSrv
http://errors.angularjs.org/1.6.9/$injector/unpr?p0=variableSrvProvider%20<-%20variableSrv.

I remember a day before I edited a Dashboard provided by the PCP plugin and saved it. Did that break it all?

Thanks.

Hi,
I have the same problem with another plugin (CSV-plugin).
grafana_plugin_error
Can you help me ?
Thanks !