I've built an MVC test application by sencha command, then I've built package: everything has been ok.
Then I've added a grid panel but rendering has been wrong: white headers, no row/column lines, no popup from headers, no possibility to select rows.
I've solved the problem by replacing MyApp\build\production\MyApp\resources with ext-4.2.1.883\resources\ext-theme-classic and renaming ext-theme-classic-all.css with MyApp-all.css.
It seems that my previous resource folder has been incomplete.
My solution seems to me "dirty". Anybody can suggest me a better solution or explain me why sencha command created an incomplete resource folder?
Best regards
Francesco