Some help with getting started

[GordianDziwis]

I have coc running and installed wmclient.

My configuration is:

let g:vim_mediawiki_site = 'en.wikipedia.org'
let g:vim_mediawiki_completion_prefix_length = 1
let g:vim_mediawiki_completion_limit = 100
let g:vim_mediawiki_completion_namespaces = {
\   'en.wikipedia.org': {
\       '[[': 0,
\       '[[Talk:': 1,
\       '[[User:': 2,
\       '[[User talk:': 3,
\       '[[Wikipedia:': 4,
\       '[[Wikipedia talk:': 5,
\       '[[File:': 6,
\       '[[:File:': 6,
\       '[[File talk:': 7,
\       '[[MediaWiki:': 8,
\       '[[MediaWiki talk:': 9,
\       '[[Template:': 10,
\       '{{': 10,
\       '[[Template talk:': 11,
\       '[[Help:': 12,
\       '[[Help talk:': 13,
\       '[[Category:': 14,
\       '[[:Category:': 14,
\       '[[Category talk:': 15,
\       '[[Portal:': 100,
\       '[[Portal talk:': 101,
\       '[[Book:': 108,
\       '[[Book talk:': 109,
\       '[[Draft:': 118,
\       '[[Draft talk:': 119,
\       '[[TimedText:': 710,
\       '[[TimedText talk:': 711,
\       '[[Module:': 828,
\       '[[Module talk:': 829,
\   },
\ }

Then I open test.wiki and type [[Ge..., but no completions beside snippets appear.
:CocList sources shows that the mediawiki source is enabled.
Where do I start do debug this?