Uncaught TypeError: Cannot read property 'current' of undefined react-dom.production.min.js:134 at Vg

Question

My server went suddenly blank and i got following error message in browser console:

Uncaught TypeError: Cannot read property 'current' of undefined react-dom.production.min.js:134 at Vg...

What can be the issue? Something wrong with the react CDN server`?

My script in the html is:

<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.production.min.js"></script>

In development mode the message is (from my development enviroment):

(index):1 Access to script at 'https://unpkg.com/[email protected]/umd/react-dom.development.js' (redirected from 'https://unpkg.com/react-dom@16/umd/react-dom.development.js') from origin 'http://localhost' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. unpkg.com/[email protected]/umd/react-dom.development.js:1 Failed to load resource: net::ERR_FAILED App.js:63 Uncaught ReferenceError: ReactDOM is not defined at App.js:63

My react components are translated from jsx to js with Babel web page. Presets: es2015, stage-2

I got the main application up by dropping "crossorigin" from the script. But it works only in development mode, not in production mode.Server is up but slow. And it shows

[Violation] 'react-invokeguardedcallback' handler took 262ms react-dom.development.js:128

Headers in production mode

Request URL: https://unpkg.com/[email protected]/umd/react-dom.production.min.js
Request Method: GET
Status Code: 200 
Remote Address: 104.16.126.175:443
Referrer Policy: no-referrer-when-downgrade
access-control-allow-origin: *
cache-control: public, max-age=31536000
cf-cache-status: HIT
cf-ray: 4a4e1438e86e5af7-HEL
content-encoding: br
content-type: application/javascript; charset=utf-8
date: Wed, 06 Feb 2019 13:49:15 GMT
etag: W/"1a24b-tnTtN6dcAkNhpzBK8ZBEsa24AAw"
expect-ct: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
last-modified: Sat, 26 Oct 1985 08:15:00 GMT
server: cloudflare
status: 200
strict-transport-security: max-age=31536000; includeSubDomains; preload
vary: Accept-Encoding
x-cloud-trace-context: 7ef73148e43be758d63b9525cae9fe1c
x-content-type-options: nosniff
:authority: unpkg.com
:method: GET
:path: /[email protected]/umd/react-dom.production.min.js
:scheme: https
accept: */*
accept-encoding: gzip, deflate, br
accept-language: fi-FI,fi;q=0.9,en-US;q=0.8,en;q=0.7
origin: https://www.suomiverkko.online
referer: https://www.suomiverkko.online/
user-agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36 OPR/57.0.3098.106

Answer 1

It started working when i load these files from my own server. Obviously the issue was some sort of network issue somewhere.