Error spam while typing YAML file in "tasks" folder

While editing a yaml file under certain conditions, an error occurs in VSCode (I'm not sure what this window is called). The error causes the window to reopen on almost every character typed, even after closed.

[Error - 6:48:02 PM] Request textDocument/completion failed.
  Message: Request textDocument/completion failed with message: Cannot read property 'type' of undefined
  Code: -32603 

I believe this is the smallest steps to reproduce:

1. Folder named tasks
2. Any file ending in .yml inside it (I used test.yml)
3. In that new file, type the following (don't copy paste):

- n

and that will give you the error (upon typing the n).

Let me know if anymore information is needed or if reproduction isn't possible.

Reproduce the failure in VS Code with a tasks folder, a .yml file, and the typed content "- n". Start by tracing the textDocument/completion request that reports "Cannot read property 'type' of undefined"; done means typing no longer repeatedly reopens the error window.