[BUG] `Nn.diagnosticManager.getDiagnosticList` is not iterable

[jackielii]

Describe the bug

When first start up, an error message shows:

[coc.nvim] Nn.diagnosticManager.getDiagnosticList is not a function or its return value is not iterable

Result from CocInfo

## versions

vim version: NVIM v0.7.0
node version: v16.15.0
coc.nvim version: 0.0.80-fbc8b5f 2022-05-04 23:47:28 +0800
coc.nvim directory: /Users/jackieli/.config/nvim/plugged/coc.nvim
term: tmux
platform: darwin

## Log of coc.nvim

2022-05-05T16:51:01.819 INFO (pid:83018) [services] - registered service "languageserver.ccls"
2022-05-05T16:51:01.820 INFO (pid:83018) [services] - registered service "languageserver.dockerfile"
2022-05-05T16:51:01.821 INFO (pid:83018) [services] - registered service "languageserver.bash"
2022-05-05T16:51:01.894 INFO (pid:83018) [coc-git] - Looking for git in: git
2022-05-05T16:51:01.898 INFO (pid:83018) [services] - registered service "highlight"
2022-05-05T16:51:02.068 INFO (pid:83018) [plugin] - coc.nvim initialized with node: v16.15.0 after 308ms
2022-05-05T16:51:02.071 WARN (pid:83018) [workspace] - workspace.createStatusBarItem is deprecated, please use window.createStatusBarItem instead. 
    at Object.t.initStatusBar (/Users/jackieli/.config/coc/extensions/node_modules/coc-spell-checker/out/index.js:1:155873)
    at Object.t.activate (/Users/jackieli/.config/coc/extensions/node_modules/coc-spell-checker/out/index.js:1:23099)
2022-05-05T16:51:02.211 INFO (pid:83018) [attach] - receive notification: runCommand [ 'explorer' ]
2022-05-05T16:51:02.227 INFO (pid:83018) [attach] - receive notification: doAutocmd [ 1 ]
2022-05-05T16:51:02.228 INFO (pid:83018) [attach] - receive notification: runCommand [
  'coc-helper.internal.didVimEvent_m1_v0_13_0_coc_helper_1',
  'BufDelete',
  2
]
2022-05-05T16:51:02.228 INFO (pid:83018) [attach] - receive notification: runCommand [
  'coc-helper.internal.didVimEvent_m1_v0_13_0_explorer_2',
  'BufDelete',
  2
]
2022-05-05T16:51:03.053 INFO (pid:83018) [attach] - receive notification: highlight []
2022-05-05T16:51:08.009 INFO (pid:83018) [attach] - Request action: doKeymap [ 'explorer-key-n-q' ]
2022-05-05T16:51:08.038 INFO (pid:83018) [attach] - receive notification: doAutocmd [ 1 ]
2022-05-05T16:51:08.453 INFO (pid:83018) [attach] - receive notification: highlight []
2022-05-05T16:51:10.179 INFO (pid:83018) [attach] - receive notification: showInfo []

Steps to reproduce Steps to reproduce the behavior:

1. execute nvim
2. :CocCommand explorer
3. See error

Expected behavior

No error message

Screenshots

Additional context

I believe this happens when the language server is not initialised? IIRC this only happens when I first open it up