Could you please provide more details on how it's happened?
Do you upgraded Plesk server or it's a clean installation? What actions were done before you get an error?
Ideally, if you provide step-by-step instruction how do we can reproduce the issue.
It's a clean installation, but I migrated a domain from a previous version of plesk.
OS: Ubuntu 18.04.2 LTS (GNU/Linux 4.15.0-50-generic x86_64)
This domain has a wordpress installation.
I'm trying to get Plesk to register it, so I'll have Wordpress (in the main menu) and then actions -> detect.
But I get this error:
vhostmng-find failed: Unable to process "./.gnupg": No such file or directory
Segmentation fault (core dumped)
I moved the folder and I got to detected the wordpress.
Such errors could indicate possible hardware issues on the target machine where the website was migrated. IMHO, the best way is to contact our support Plesk Help Center for deep investigation.