I thought I had fixed #3 (I was able to run locally by upgrading to Vaadin 14.8.20) but:

• mvn jetty:run fails same error occurs when upgrading to Vaadin 14.9.0, 14.9.3
• The same error occurs when compiling the demo site in production mode with Vaadin 14.8.20
• The demos for 22.0.25, 23.2.10 and 24.0.0.alpha6 are not affected.

ERROR in J:\fc\addons\fc-addons-demos-14\node_modules\@types\express-serve-static-core\index.d.ts
[tsl] ERROR in J:\fc\addons\fc-addons-demos-14\node_modules\@types\express-serve-static-core\index.d.ts(99,68)
      TS1110: Type expected.