"ERR Webview.loadLocalResource" trying to load `codicon.css`

[bersbersbers]

I am seeing this in the Developer Tools console:

ERR Webview.loadLocalResource - Error using fileReader. requestUri=file:///c%3A/Users/xxx/.vscode/extensions/raywiis.png-image-diff-0.0.49/node_modules/%40vscode/codicons/dist/codicon.css, resourceToLoad=file:///c%3A/Users/xxx/.vscode/extensions/raywiis.png-image-diff-0.0.49/node_modules/%40vscode/codicons/dist/codicon.css

It looks like it's looking for icons in a folder that is not bundled as part of the extension.