500 Error After Upgrading 13.12.10 to 14.0.X

We have attempted to upgrade from gitlab-ce-13.12.10 to version 14.0. We are using the omnibus edition of gitlab on Centos 7. When we upgrade from 13 to 14 we are presented by a 500 error in the browser. Looking through the logs it appears the issue relates to gitlab-rails assets, yet according to all the documentation I can find we shouldn’t experience issues with it. The extract from the logs is:

Completed 500 Internal Server Error in 15ms (ActiveRecord: 0.8ms | Elasticsearch: 0.0ms | Allocations: 8781)

ActionView::Template::Error (No such file or directory @ rb_sysopen - /opt/gitlab/embedded/service/gitlab-rails/public/assets/themes/theme_indigo-b2e36d3529265074efbd
1959fa952f65c267366dcc6f52ae8f8ca8f8cab1601a.css):
1: - startup_filename_default = user_application_theme == ‘gl-dark’ ? ‘dark’ : ‘general’
2: - startup_filename = local_assigns.fetch(:startup_filename, nil) || startup_filename_default
3:
4: %style
5: = Rails.application.assets_manifest.find_sources(“themes/#{user_application_theme_css_filename}.css”).first.to_s.html_safe if user_application_theme_css_file
name
6: = Rails.application.assets_manifest.find_sources(“startup/startup-#{startup_filename}.css”).first.to_s.html_safe

Any assistance on figuring out how to fix this issue is greatly appreciated. We have attempted going to 14.0.7 and 14.0.0, both causing the same issue.

Thanks!

The issue has gone away after we did a yum update (excluding gitlab-ce from the update).

I have the same error in the log

"exception.message":"No such file or directory @ rb_sysopen - /opt/gitlab/embedded/service/gitlab-rails/public/assets/startup/startup-signin-c21565283bb085caf6b4f86276f13302506b9f3001736c14862c431142b32b9c.css",

"exception.backtrace":["app/views/layouts/_startup_css.haml:5:in `each'",

The file is not existing.
Running on Debian Buster .
Executed
sudo gitlab-ctl reconfigure
sudo gutlab-ctl restart

and apt-get update/upgrade

does anyone have an idea?

thanks in advance!