Fixing Strapi CMS preview issue
If you trying to setup Strapi CMS and you see this issue with previews
You just need to configure security plugin in the middleware
{ name: 'strapi::security', config: { contentSecurityPolicy: { useDefaults: true, directives: { 'connect-src': [ "'self'", 'https:' ], 'img-src': [ "'self'", 'data:', 'blob:', 'storage.googleapis.com', 'market-assets.strapi.io' ], 'media-src': [ "'self'", 'data:', 'blob:', 'storage.googleapis.com', ], upgradeInsecureRequests: null, }, } } }https://docs.strapi.io/cms/configurations/middlewares#security