If you’re looking for some help, it’s important to provide as much context as possible so that people are able to assist you. Try to always mention:
What’s your URL? This is the easiest way for others to debug your issue
N/A (frontend shows an error about missing template/theme)
What version of Ghost are you using?
DO, Ubuntu 18.04, nginx 1.16.0, mariadb 10.1.38, node 8.16.0
What errors or information do you see in the console?
There is no error in the console, just the frontend shows missing theme, even though the theme exists in the content/themes/ folder
What steps could someone else take to reproduce the issue you’re having?
Export content from Labs to json file and them import it into a newly setup Ghost blog where you already copied over (and overwritten) the content folder. The themes exist in the content/themes/ folder, but they do not show into the Design admin area and need to be reinstalled manually.
4 drwxr-xr-x 6 ghost ghost 4096 May 3 17:01 WorldCasper2-2.7.0
0 lrwxrwxrwx 1 ghost ghost 51 May 4 20:45 casper -> /var/www/secareanu.ro/current/content/themes/casper
4 drwxr-xr-x 4 ghost ghost 4096 Dec 6 13:48 massively-master
4 drwxr-xr-x 6 ghost ghost 4096 Dec 6 13:46 worldcasper2-i18n-translatable-frontend
While in the admin the installed themes are:
For Casper, this is (most probably in my specific case) because moving over the content folder also moves absolute paths from previous server to the new one (and they are different in this case). For example, on the previous server I had sites at /srv/www/ while on the new server they are sitting at /var/www/ so the sym links to Casper are broken because the old path is no longer valid. Maybe a solution would be not to use absolute paths (if it makes sense).
Later edit: It seems that after fixing Casper’s broken link and restarting Ghost the other themes in the folder start to show up in the admin.