Refused to load the script 'https://www.arcgis.com/sharing/rest/portals/self?f=json&callback=dojo.io.script.jsonp_dojoIoScript1._jsonpCallback' because it violates the following Content Security Policy directive: "script-src 'self' js.arcgis.com 'unsafe-inline' 'unsafe-eval'".
s._attach @ init.js:396
init.js:356 dojo.io.script error k {message: "Timeout exceeded", response: Object, log: undefined, stack: "Error: Timeout exceeded↵ at k [as constructor] … at f (https://js.arcgis.com/4.0/init.js:178:388)"}
Uncaught TypeError: Cannot read property 'lods' of null
at Object.getZoom (VectorTileLayerView2D.js:8)
at Object.<anonymous> (VectorTileLayerView2D.js:5)
at d (init.js:77)
at h.isActive.c [as callback] (init.js:77)
at h._dispatch (init.js:83)
at c (init.js:90)
at MutationObserver.observe.attributes (init.js:91)
Also couldn't hurt to bump to a more recent version of 4.x.