Blank screen after upgrade to U17.4.0

Questions
1

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.