[Qgis-user] Couldn't load plugin XY due to an error when calling its classFactory() method

[Johannes Kröger (WhereGroup)]

> (@gary: I'm not sure but I think this comes from the plugin builder, 
> is that possible?)
>
Yes, 
https://github.com/g-sherman/Qgis-Plugin-Builder/blob/e51befa0ab980a57311c6f33d8d026d02da21cc3/plugin_templates/toolbutton_with_dockwidget/template/module_name.tmpl#L53

Funnily enough I ran into this issue just today too, with no special 
setup but a clean new profile I created yesterday and had been using in 
a training since. Not sure what could have caused the key to get 
removed. I had switched between system locale, English and back once. 
The first plugin I installed crashed with this.

Cheers, Hannes