Enable SMTP Host I get an error

New installation
Ubuntu 18.04.3
set APP_DEBUG=true in .env

Enable SMTP server. When I enter a value in the SMTP server I get belwo error direct.

Method Illuminate\Validation\Validator::validate^[aZAZ09.]+$ does not exist.

A new bug just introduced, thanks for reporting.
It is fixed now, just run ./daily.sh as the librenms to fix (or wait a day)