Initially tried to Add Perl-LanguageServer on projectj website.
Then used Perl-LanguageServer - CPAN Dependencies Graph
to determine dependencies and tried to Add those missing (all were able to be Added, all Auto)
But it still had the same result, and no errors nor missing modules listed.
Is there a link to a generated log file or something that would give some hint of what it wants ?
Looks like it is working now. That is one huge project!