I have copied the database of my production site to my dev site and my theme is not working anymore (on the dev). The content (nodes) is not exactly the same, but theme folder is.
All the information in the CSS files is still displaying but the settings in
admin/appearance/settings/corporateclean (UI for basic colors) have no effect anymore.
The logs show the following warning:
Theme key "0" not found.
I have tried flusing the caches, de-activate cache pages, CSS aggregation without success. I had the issue in the past and copying all the files fixed it but it's a brute force fix and I'd like to understand what happens. I am 100% sure the theme directory is up to date, so some other files may be messing. Any idea?