zk is a command-line tool helping you to maintain a plain text Zettelkasten or personal wiki. It provides a Language Server to augment LSP-compatible editors with many features such as auto-completion and navigation.
zk-vscode is a Visual Studio Code client extension for zk's Language Server.
If you experience issues with zk-vscode, you can peek at the Language Server logs with the zk: Show Logs VS Code command. To get more detailed logs, set the verbose mode in your settings.json: