https://geoext.github.io/geoext/master/examples/filtered-heatmap/filtered-heatmap.html is broken and fails with GeoExt.data.store.Features needs to be configured with a feature collection or with a layer with a source with a feature collection, most probably broken since Enforce collections for feature store. #686

https://geoext.github.io/geoext/master/examples/features/grid.html has the same issue

https://geoext.github.io/geoext/master/examples/features/grid-filter.html has the same issue

https://geoext.github.io/geoext/master/examples/features/grid-map-selection.html tries to load https://geoext.github.io/geoext/master/src//selection/FeatureModelMixin.js but gets a 404, there are probably follow-up errors

https://geoext.github.io/geoext/master/examples/print/basic-mapfish.html fails with Uncaught DOMException: Failed to execute 'drawImage' on 'CanvasRenderingContext2D': The image argument is a canvas element with a width or height of 0.