Blank screen after upgrade to U17.4.0

Hi, I’ve just upgraded my production site from U17.2.2 to U17.4.0. The web site is fine but trying to access the Umbraco backoffice just gives a blank screen. The only errors I’ve found are three javascript errors in the console, as follows:

Failed to load resource: the server responded with a status of 404 ()

https://mywebsite.com/umbraco/backoffice/ca044cf5853771a09faef2c515e1386e9413eda7/packages/core/umb-auth-view.element-C7YFpvLN.js

https://mywebsite.com/umbraco/backoffice/ca044cf5853771a09faef2c515e1386e9413eda7/packages/core/switch.condition-Co0RLjdv.js

https://mywebsite.com/umbraco/backoffice/ca044cf5853771a09faef2c515e1386e9413eda7/packages/core/umb-collection-view-element-base-B3ZU6Ikw.js

The part of the folder path ca044cf5853771a09faef2c515e1386e9413eda7 looks wrong (after reviewing the contents of the umbraco/backoffice folder.

Anyone have any ideas on how to resolve this?

Thanks.

Hi @johnsmith

That folder path is actually fine. The backoffice uses a cache buster, which is the hash you’re seeing in the URLs. It’s a virtual path segment based on the Umbraco version, so you won’t find a matching physical folder under /umbraco/backoffice.

The 404s suggest your browser has cached the old 17.2.2 entry point, which references files that no longer exist in 17.4.0. Try a hard refresh (Ctrl+F5), an incognito window or a different browser.

If that doesn’t fix it, check whether a CDN or proxy (e.g. Cloudflare) is caching /umbraco/* and purge it. There’s a recent thread on this here:

Justin

Hi Justin,

Thanks so much for your reply. You put me on the right track - in my case, the assets weren’t copied up. I was copying the files to the server but my RDP connection was a bit ‘spotty’ and some files didn’t get copied over. It’s all working now.

Thanks again.