Backend Inaccessible Following v4 Upgrade

Hello! After upgrade to v4 I have this error at /ghost backend so I am unable to login or access the admin of my Ghost site:

404 Cannot find module '…/…/…/…/frontend/helpers/asset’

The public-facing site seems all right… The site is here:

Any clues would be much appreciated!!!

[namespac@txpro11 DENVERGEEKS.COM]$ ghost doctor
✔ Checking system Node.js version
ℹ Ensuring user is not logged in as ghost user [skipped]
ℹ Checking if logged in user is directory owner [skipped]
✔ Checking current folder permissions
✔ Validating config
✔ Checking memory availability
✔ Checking binary dependencies
✔ Checking free space
[namespac@txpro11 DENVERGEEKS.COM]$ ghost stop

Ghost is already stopped! For more information, run:

    ghost ls

[namespac@txpro11 DENVERGEEKS.COM]$ ghost start
ℹ Ensuring user is not logged in as ghost user [skipped]
ℹ Checking if logged in user is directory owner [skipped]
✔ Checking current folder permissions
✔ Validating config
✔ Checking memory availability
✔ Checking binary dependencies
✔ Starting Ghost: DENVERGEEKSWEBSITE

------------------------------------------------------------------------------

Your admin interface is located at:

    https://denvergeeks.com/ghost/

[namespac@txpro11 DENVERGEEKS.COM]$

This too…

I went ahead and moved the site files into a fresh installation of Ghost 4, since even restoring a site backup from last week did not change the error. A mysterious glitch though…